Rule #1 - Generally and almost without exception anyone who actually has inside info doesn't share it via twitter, Cougarboard or any other form of communication (including to their neighbor, buddy, former mission comp, etc). There may be some people that let slip a few little tidbits or generalities, but most people privileged enough to actually know something meaty don't share - with anyone (especially the kind of person who would then go and spill it on a message board).
Rule #2 - Most people that share inside info on twitter, Cougarboard or other forms of communication don't have firsthand accounts of the information they share. They usually get it from someone they know. So, given rule #1 it goes without saying that most information shared like this is usually not worth much.
Rule #3 - Even knowing rules #1 and #2 aren't usually enough to stop the average person from hoping that some rumors are true or not true and starting to hope/believe that a certain poster actually does have inside info. Nothing really wrong with that (been there myself) as long as you understand rules #1 and #2 sufficiently well.
Rule #4 - Any inside information shared with the public is almost always calculated. People on the inside don't share inside info to stroke their egos or because they believe so strongly in the freedom of information. They generally share things to accomplish something. That doesn't mean the information isn't legitimate, but it should make the receiver question why this piece of information was allowed to leak in the first place.
Rule #5 - Inside info is fun. That's why everyone cares when it comes out. Just remember that everything gets colored to some extent through the lenses of the person spilling the inside info.
Rule #6 - The most dangerous inside info sharers are those who try the hardest to make you think they are legitimate or have legitimate information - in other words, they try and get you to forget one of the aforementioned rules. Beware the sharer of inside info who takes great offense at not being believed or tries inordinately hard to get people to believe them as a legitimate source. In fact, it's probably a good idea to generally view skeptically anyone who shares any inside info at all. Doesn't mean it couldn't be true, but chances are you're either getting half the truth at best. Sifting through information with these qualifications can actually enhance the experience - a grain of salt is a good companion for any CBer.