There is no perfect system.
Scanners, barcodes, etickets, exploding nanobots to stalk those without badges....
There will always be thieves and innocent victims of delivery problems.
With that said....get this...in two of the three years of my Gencon experience, I have either lost a badge or even worse, a wallet (and therefore no ID for purchasing tickets LOL.) In both instances, Gencon was extremely graceful and 'with it' in managing the situation.
As things are, Gencon is forced to deal with matters on a case by case basis, and the current policies allow them great flexibility in doing so. Approach is everything (for both sides) and if you get a customer service rep who can't help you, keep climbing up the ladder. It shows resolve.
The con artiste who goes through seemingly earnest measures is probably better saving such an act for robbing a bank than getting a free badge. Karma will eventually smoosh such a weed anyway -- I mean c'mon...considering the cost ($75) and the subculture (gamers) who is going to go out of their way to slime their way to a free badge? Sad thing is, I'm sure there are a few, but the numbers can't be THAT high, and if they are, I'd be cautious of hosting an event in such a den a thieves let alone attending.
My instinct: for every 1,000 honest attendees, there is perhaps one miscreant set upon thwarting Gencon for a $75 badge.
Until things are changed, the best policy: will call.
That reminds me: how did the badge scalping on the streets go last year? If we change the system, won't we be crushing an important secondary badge market? :p JK of course.