The mass use of fake IDs of this sort is a bizarrely American problem. In the UK, you're considered an adult at age 18. Most (aside from the unfortunate 17-year-olds) university students can legally purchase alcohol, smoke, or gamble if they so choose. But we don't have MADD, I guess.
In the late 90s, when I was 16-17 and doing my A levels in the South East, plenty of people had fake "Prove It" cards and the like.
If you wanted to grab a drink at anything but the most desperate of pubs or go out in e.g. Brighton, you didn't have a hope unless you could prove your age.
Funnily enough, I knew plenty of 18 and 19 year olds that also used fake IDs, just because getting a more legitimate form of ID was a bigger pain than they could be bothered with - and taking your passport out seemed a bit over the top.
I dunno, maybe I just hung out with the wrong crowd?