Apparently, stealing elaborate beer glasses has become quite a popular trend among patrons of Belgian beer bars, so much so that in recent years bar owners have started implementing all sorts of measures to try to prevent it. For example, one bar asks visitors to hand over one of their shoes as collateral.
Philip Maes, owner of The Beer Wall bar in Bruges, said that he loses over 4,000 beer glasses a year, which can get pretty expensive. A beer glass can cost up to 50 euros ($55), so having thousands of them stolen adds up to a significant financial loss. So Philip and other bar owners have implemented security measures to discourage beer glass thefts.