I saw a lot of this for awhile at a church I used to attend. There was one group of people that were always "prophesying" over others. It always looked like a circus to me when they did this and always disrupted the service. What was disconcerting to me about it was that it really seemed like these folks loved the Lord and tried to live their faith, but then they'd break out prophesying, and seemed to be able to turn it on at will, whenever they wanted to. I was a fairly new Christian at the time, so didn't know God's Word any where near as well as I know it now, but something just seemed very wrong with it all. These same folks were also very much into "healing" and didn't seem to think there was any reason that anyone should ever be sick. It seemed like a personal affront to them if someone wasn't healed instantly, yet no one ever was.
At first I'd listen to their prophesies very carefully and they were often quite specific. They'd tell people things like: "God is going to see to it that you come into a lot of money very soon so you can start a TV station that will honor Him and bring many into the Kingdom". That one really floored me and I waited expectantly to see it happen. Of course it never did and it's been over 15 years now.
They seemed to know the pastor well and often prophesied over him or his wife. I remember once they told her that God was going to give her her own ministry and how great it was going to be. I knew that the pastors wife was already busier then any two women usually were, so I wondered how He was going to make any more time for her to do something else. That one was difficult to determine if it came true or not. As far as they were concerned it did, but I wasn't so sure. She did later start a women's ministry, or rather she got it going for others anyway. But she'd done that many times in the past and I knew she'd continue to do it in the future, so it wasn't anything new and it certainly wasn't what their entire prophecy had seemed to indicate. That particular ministry fizzled out after a short time anyway.
I noticed that when these people did give a prophesy, it was always something spectacularly good for the person and often involved the person getting money which of course they always said was to be used for something that would bring glory to God. But then according to the things they'd say, anything could bring glory to Him, including just paying your bills. Which is true I suppose, but it just didn't sit right with me.
These folks also spoke in tongues and often preceded their prophecy by speaking in tongues or would prophecy in tongues first and then they'd interpret it for us. What I thought was strange was that no one else could ever interpret anything one of them said in tongues, only the person who spoke it could. Nor was there ever anyone who could or would stand up in agreement or disagreement with anything they prophesied.
There were others besides this core group of course. Over the years there always seemed to be a few folks that were really into this kind of thing.
Of course I asked the Lord about it and He had me study all the times a prophet spoke in the NT and then the OT. What I found interesting was that the vast majority of times, the prophecy wasn't nice, it wasn't something anyone would necessarily want to hear. Like when the prophet told (and demonstrated) how Paul was going to be arrested and put in chains; another common thing for the prophets to prophesy was to tell the person or persons that they were sinning and not doing God's Will. I just couldn't find anywhere where a prophet had spoke words anything like what these folks did regularly.
Having been saved out of the New Age and Occult garbage, I was very aware of psychics and what they did.Just as the article above pointed out, that's exactly what these people reminded me of. Thankfully I've never heard of seen of any of them giving prophetic "readings" around here though. I'm afraid I've have to speak a few words to them if so.
But then the Lord shocked me by giving me what I later came to understand were sometimes called either "words of knowledge" or "words of wisdom". Well, at least that's the closest thing I could come to for what He told me. Don't worry. He never told me things like "so and so's going to come into a lot of money" 
Anyway, after more then a year, the Lord finally gave me confirmation that showed me for absolute sure that I'd been hearing from Him and been doing His Will. At first various people that I'd been praying for would come up to me and say things in conversation that would confirm that I'd been praying for the right things. It was always a shocker to everyone, even me, even though I'd been praying for them about it. For instance a woman who I had always thought had a wonderful marriage and family, and who'd never given any indication that anything was wrong, announced that she had filed for divorce several months before but was now reconciled with her husband. 
Of course I immediately, for the first time, asked the Lord for permission to share that there had in fact been someone praying for them, and He gave it. I still remember writing that reply to them. I had tears streaming down my face. I told them the whole story of how the Lord had asked me to pray for them and how I had been doing so and for how long; and how He'd awakened me that particular night at that time, telling me to pray and pray hard! So I prayed and I kept praying until I felt completely at peace and knew I could stop. Needless to say, they too were astounded at just how much God loved them.
It still astounds me too, as I too had a time in my life when I thought no one cared about me enough to pray for me and I desperately needed prayer. I have no doubt in my mind though, that God made sure I was covered in prayer then, just as He did for this person. I know He does it for all of His children, because He loves us so.
So now you can see that while I don't for a moment believe any of those other people were speaking for God, I do believe that God speaks to us and even gives us insight and wisdom we need to do His Will. It's not something to be used to show off and look important to others, and not to interrupt a service with. Nor is it to tell people that "everything's going to be ok, that they'll get the money they need, their relationships will be repaired, etc. No. It's only to do His Will and help His children and to build up the body of Christ. So please, beware of those who have "words of knowledge or wisdom" for you, or who prophesize over you. Test them against the Word of God, and if it's not there, then the Word isn't from God.
2 Cor 13:1; 1 Cor 14:26–28; 1 Cor 14:29–30; 1 Cor 14:32–33;
Part 2:
I think most of these folks are well meaning people who love the Lord and want to do great things for Him, want to please Him, but have wound up being misled as to how to serve Him. I know for example that a great many churches tell people to "practice" speaking in tongues, to literally fake it and that then one day it will just "happen" for them. I was told that by any number of churches even, and I'm not pentecostal. It's the same with words of knowledge and wisdom. People are told to just say whatever comes into their minds and "believe it's from God". They're not taught discernment or accountability. Since that's what they're told, and what they hear from others all the time, they assume that's the correct way it's done.
The most dangerous thing I've seen in many churches is people "practicing" hearing from or trying to receive messages from the Holy Spirit. It's similar to getting words of knowledge or wisdom and yet different. It's hard to explain. It's yet another way that Satan has deceived the elect because in this case instead of just saying whatever comes into their heads, like so many do with the words of knowledge and wisdom, they actually begin to hear from demons. Without realizing it, they're doing exactly the same thing the new agers do when they hear from their so called "spirit guides". These people become more and more deceived as time goes by and often don't realize it for many years. They think they're having a special experience and as you know, we humans just love supernatural experiences and tend to cling to them. Plus of course it makes them feel "special" too, all of which makes it even harder for them to repent. Since these people really do love the Lord, they have a really hard time believing that they've been fooled by Satan for all that time. That too makes it hard for them to truly repent, because to repent we must first agree with God that what we've been doing is a sin. Somehow, to us, when we sin in these ways, it seems worse to us then if we'd lied or done some kind of "regular" sin. I guess that's part of the problem, that we tend to categorize sins that way and forget that what matters is that we repent, not what the sin was.
I've noticed though that when someone who was involved with that does truly repent, they seem to become even more on fire for God and really study His Word more then ever as they don't ever want to get caught in one of Satan's schemes again. Because of that, they grow quickly and the more they grow the more they study... it's like a circle and it effects everyone around them. I can easily see the Lord using them to do great things in their lives and the lives of all who know them after they truly repent though, as they seem to be the type that feels His Word is like a fire within them that they have to release, only now they realize that His Word isn't something put or heard in their minds, but is in their Bibles. Its amazing what God can do with us when we repent and do things His way!
Jeremiah 20:9 —But if I say, “I will not mention him or speak any more in his name,” his word is in my heart like a fire, a fire shut up in my bones. I am weary of holding it in; indeed, I cannot. *
Job 32:18–20 —For I am full of words, and the spirit within me compels me; *inside I am like bottled-up wine, like new wineskins ready to burst. *I must speak and find relief; I must open my lips and reply. *
But I can see it's preparing the way for the Mark. People in America are getting more and more used to being told what they must do. 
When I could get the words out, I finally asked her what the "good news" was. She said that because of the situation, we wouldn't have to pay the penalty. So the bottom line is that we're too poor to get insurance of any kind, but that obama will at least let us off the hook so we won't have to pay the penalty. Isn't that nice of him????