I've been getting more and more of these requests at Infoshop. Typically people who wrote something years ago which we published. I had to remove our last podcast from the Internet last month after the subject of an interview asked that the podcast be taken offline. Another librarian comrade asked me last year to remove an interview we did with her several years ago. She cited a job search as the basis for her request.
I have mixed feelings about these requests. As Doug points out, they are time-consuming. If more and more people try to erase their past from the Internet, even postings to Internet lists, we all lose our freedom. I can sympathize with these people because I'm certain that my job search has suffered because of employer Google discrimination against me. It's hard to say for sure, but I have to expect that a potential employer here and there have dug up some of my political activities.
I'm really pessimistic about this because nobody is doing anything to confront employers about this. The labor movement isn't going to do anything because the mainstream unions are too busy making money and sucking Democratic Party cock.
Part of the problem also lies with our comrades, who tend to follow the same ignorant ideas about discussion lists that other Internet users hold. People still don't understand that a mailing list discussion, while being archived and a written form of discourse, is still an informal kind of discussion. I always treat the discussion here on LBO-talk list as if it was a political discussion at a bar or restaurant. Some of the more dim bulbs on this list take it as a form of publication and dig out quotes from people out of the archive to make points. Really, folks, I don't care what you posted here about an issue a year ago and you shouldn't care about something I wrote here two years ago. People do change their positions. And people are more casual here and aren't as precise as they are in formal written discourse.
Chuck