[wmf]

A single user that constantly gets attacked by hackers would provide a great opportunity to detect and fix security holes.

Assuming that they want to fix the holes, which AT&T probably doesn't. They may be using the "infinite bugs" model, in which fixing one bug does not improve security because there are always other bugs the attackers can find.

[Tichy]

Brilliant - an infinite number of bugs might confuse hackers so much that they don't know where to start and just give up.