Messing with people's facebook account when they leave it logged on - e.g. posting funny or embarassing statuses, changing someone's birthday, changing profile pictures.

Used instead of frape to avoid trivialising rape and re-traumatising rape survivors - just generally a less unpleasant word for a lighthearted joke.
"Bob posted 'just took a massive shit'"

Bob: "yeah, that was a tresspost guys"
by Feminist Bob March 6, 2014
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