Spoken like someone who's never actually BEEN to E3.
Here's how it works, people.
1. Register On-Line.
2. Get badge in the mail.
3. Go to E3.
4. Go to the registration booth (no, you're not REALLY registered yet), and show your ID and other credentials.
5. Get your Badge HOLDER for your badge.
6. Get your badge checked visually by a guard on your way in.
Now, people seem to think it's as easy as copying a badge. It's not. The badges have a "code" on them, and it matches up with the COLOR of the badge holder you get at the second part of registration. The guards can see this sort of thing at a distance, which is why it looks like they aren't really paying attention. They are.
For some of the more EXCLUSIVE events within E3 (like the media breakfast), you need to get your badge scanned on the way in.
I'm not saying it's not possible to bluff your way in. But it's not as easy as parasyght would have you believe. However, I've seen a lot of people kicked out of the show thinking that they had it made.