It's kind of like an "I'm not guilty of anything illegal" statement if your postings were to be used as evidence against you in a criminal investigation. They most likely wouldn't actually mean shit in court but people do it for fun more than anything, I guess. It's like saying SWIM (Someone Who Isn't Me) in a post instead of saying "I just manufactured schedule I drugs in my kitchen"
The Earth
It spins and shakes
It spits you out
It knows your name
I'm a pathological liar.