Thank you for making this post, I've considered making one like this myself, but I knew I could not describe is sufficiently eloquent.

What bothers me most is the fact that people really do act like the stereotypical idiot on the internet, when it's really easy not to. Just look at the people not doing it, in fact just act like you're IRL, it's not that hard. If someone comes up to you in the street and makes you an offer that sounds to good to be true, you might not even politely decline (although it would be the mature thing to do) you certainly don't scream "SCAMMM, PONNNZIIIIIII" at the top of your lungs, and even bother to come back to him and insult him, like it happens on the forums.

What I would basically suggest is that people should act more like a real world adult ... that shouldn't be too much to ask.