I think monkeys are scamming people by stealing sim cards and activating them with fake IDs. It seems the monkeys are able to get away with this because the IDs appear genuine thanks to the photo. This also falls within a legal loophole as monkeys are generally not subject to law and often fail to appear for their court date anyway so law enforcement isn't able to effectively combat the issue.
They added face recognition to the SIM registration process, in an attempt to reduce fraud. (Maybe by limiting or not allowing duplicate faces.) But a monkey face works too, and they are plentiful on the islands, supplying many unique faces.