This is strange and it needs to be shut down immediately. An ID is a legal document so it's hard to see why anything more is required. Modern ID cards are a lot more sophisticated than they were a few decades ago when a fake could be generated easily.
According to the BBC, bars in England are worried over fines for admitting underaged drinkers — often as high as $8,000. For U.K. bouncers, checking a patron's Facebook profile is a good way to weed out fake IDs. In a few short moments, the bouncer can verify a person's name and date of birth. It's not a replacement for checking a person's identification, but an extra, optional verification step.