Watched someone dissapear once. Scared me when i innocently asked about a particular member only to have my comment removed. It's only a games forum but it's a 13+ forum that introduces kids to the idea that problem people can be in effect be made an un-person for convenience sake.
Most of the time it is inappropriate to discuss a banned member, although I wouldn't say this is for "convenience sake." I could see that argument lobbied at most restricted topics, as most are restricted because they are causing problems and drawing away an inordinate amount of moderator resources. I wouldn't call this a fair label for restricting those topics, but I at least see the logic behind it. However with banned members the restriction doesn't seem to be one of convenience, but rather necessity in order to preserve the privacy guarantee.
I imagine this is an area where we will simply have to agree to disagree. If we moderated the internet as a whole the situation would be different, the stakes would be different, and the rules would be different. We're not. The primary purpose for these forums is to support games published by Bethesda Softworks, and if a topic is causing sufficient problems that we can't fulfill that we need to look at alternatives. Thankfully in most cases http://www.gamesas.com/topic/1331715-unofficial-steamdrm-discussion-26/ or creating an http://www.gamesas.com/topic/1320106-official-tes-multiplayerco-op-thread/ is sufficient to deal with the problem. But yes in rare cases we have to blacklist something entirely. We don't make these decisions lightly.