Wikipedia, yes or no?

I have heard from people in my educational experiences that using Wikipedia can be a usable source and some say it's not. Personally, I have clicked on it a few times just to see what information it has to offer for what I am researching. No matter what source we use in our studies, no-one really knows what can and can't be a trusted one, but Wikipedia one is one the weaker sources.
I am surprised to read that anyone can alter things this site. I was glad to read that there is some sort of tracking on IP addresses on those who choose to alter the information. There should be something done by Wikipedia itself if they choose to do so. If not, they we all need to find other sources for information sought. We as educators can find other sources and keep the use of Wikipedia minimal.