You clearly missed the post that has now been removed. It was a horrendous description of illegal boobytrapping that the poster used against an ex. It appeared the ex was caught in the boobytrap. He clearly was not vindictive and did not report her, so she thought it worked and suggested it to others.
An outrageous, and extremely illegal, example of boobytrapping would be to set a shotgun to go off and shoot anyone who enters the door to your apartment. There have been cases of people actually doing this, and if it hurts or kills someone, the boobytrapper is prosecuted.