This reminds me of a game we played back in the 80's called TAG.
They even made a movie about it.
I think it's been pretty much outlawed on all school campuses at this point.
the student rock society did one (smaller scale obviously)
you picked a target from an envelope and had to get them witha water pistol or a plastic sppon (the pubs plastic spoons ) the spoon had to break.
huge city scale sounds well good
Very cool stuff. I saw a couple of news segments on this game a while back, seems it's grown in popularity. Would be great to play, but I wouldn't be comfortable having a stranger stalk me for whatever amount of time your given to take your target down...