Yes, Sony's rootkey exploit has allowed unauthorized users to get unearned mod powers.
Of course, the hacker would require the console ID of a PlayStation 3 in order to ban it, which could only be done if they had access to a furbished console list - or some dolt gives them the code, or worse, some Sony rep allows them to get phished.
According to Destructoid, the mod scene is justifying its actions by calling Sony bullies and criticizing its strong-arm tactics. This does not help George Hotz's case one whit - in fact, it weakens it. The main purpose of the rootkey exploit was to allow gamers to run Linux and homebrew software on their system, not to let some yahoos pirate software and ruin other people's experience on PSN.
If true, Sony may need to recall the PlayStation 3 or produce a quick fix, because right now it's the consumers that are under the thump of these pirates. We'll have more as it develops.
<UPDATE: You can view images of the software used .>
Rumor: PS3 pirates unban selves, ban others
21 February 2011 | By JonahFalcon