Information that can be dangerous to know about. Some examples are how locking your knees too hard can cut off circulation and be lethal, or how grabbing your thumb and shaking your wrist can break an important part of your thumb. Yes, obviously there are much more dangerous things to know about, but that's up to you I guess.
Totally real person 1: Have you heard that grabbing your thumbs and shaking your wrists can break your thumb?
Totally real person 2: That's an infohazard
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.