Jimmy-
I know nothing about what was going on with Anthony Del Pierro and Eloquence.
I banned Anthony after he repeatedly vandalized the same page, even though I had told him to stop. I immediately unbanned him after the matter was resolved. I am 100% positive that this was a perfectly appropriate action to take, with arbitration committee or without, and is backed up by precedent (BuddhaInside, RK etc.). Protection was not an option, because the page in question, a list of sites using our MediaWiki software, is supposed to be openly editable at any time so that sitemasters can add their site to the list.
That being said, it would have been preferable to use a per-page ban in this case, but that feature is not yet available.
As others have also pointed out, Anthony has a long history of trolling behavior. E.g. Maximus Rex wrote: "Anthony has frequently engaged in troll-like behavior (examples include inserting Bill Gates' social security number in the opening sentence of his article (repeatedly), nominating articles for deletion that he admits he does not believe should be deleted (perhaps to prove some sort of point?), and making outrageous claims about copyright (for example at Al Gore he removed a sentence he wrote under the guise that he owned the copyright to that sentence...), and others)." In conversations with me on IRC, Anthony has also defended trolling on other websites like Kuro5hin and Slashdot.
One thing I have always been missing in the Wikipedia community is trust. There's nothing wrong with some healthy paranoia regarding all forms of authority. But I'd appreciate a little more awareness of the very real threat that persistent and annoying trolls represent to the coherence and productivity of our community. And no, these people do not have a "right" to test our defenses.
Trolls sometimes pretend to be working against "groupthink", but in reality their only goal is to disrupt things, to see how much damage they can do. Trying to deliberately sabotage the construction of a free encyclopedia takes a special, even more disgusting type of troll.
Trolling will often be very hard to prove in practice. My proposed solution is to simply give admins some leeway in enforcing the rules -- we have over 100 admins who can clean up after each other if necessary. Trolls should be treated like normal users, only that I find it fair to be especially watchful about whether they are breaking any rules, and more swift in enforcing them.
Of course I'd love to see the arbitration committee be quick in making decisions in such cases, but work by committee is rarely fast or efficient.
Regards,
Erik