I can't help but think, however, that this is a great opportunity for the creative utilisation of this - via Schneier, why not get a personalised registration incorporating an SQL injection attack? You probably can't do this in the UK, however crafty you are with where you put the bolts. (They don't make a bolt shaped like the bottom half of a semicolon, after all.)
But a T-shirt with the following message:
;INSERT INTO watchlist (pnrs) VALUES 'ADDINGTON/DMR';COMMIT TRANSACTIONThat would be cool. One of the nice things about QR codes, of course, is you can do these things graphically. Look into my eyes...
More seriously, this is one of the many things that worry me; the reason why I'm so keen on a carbon tax is that it's an option that doesn't involve creating a vast mass-surveillance system as collateral damage.