Mingegrabbing

To take something that is not yours, mostly when people are trading

Mingegrabbing often occurs in Garrysmod(a game)
mostly when roleplaying

Many people get banned from servers in garrysmod for mingegrabbing

Scenario:
Guy 1: Can you sell me some melons?
Guy 2: Yeah, sure that would be 10$
Guy 1: *Pays the money*
Guy 2: *Puts some melons on the floor*
Guy 3: *Takes the melons and run away*

Guy 1 and 2: Stop mingegrabbing!!!