There is a lot of bs online. I'd say a good 90% of the conspiracy theories that get so much attention are bullshyt but as a poster mentioned it's a big business now and folks will believe damn near anything if it's somebody or something they don't like.
People can be anonymous to a degree online so you can get a view into how people think in secret. But with all that anonymity floating around who's to say you aren't just being trolled?
Verdict? Use the net to teach yourself something you would have had to shell dollars out to learn otherwise and benefit from it.