This is kind of beating a dead horse here, but Despammed.com was my baby (still is, in an embalmed and pathetic sense) for six years. And we had Web-based anonymous email for real, written into our policy. We tossed the logs every day - the only way anybody could get fresh logs, before tossing, was to subpoena us for them. One - exactly one - law enforcement agency did that, for a user who was using us as a dropbox for credit card fraud. The Italians never managed to get us a subpoena for the freedom-of-speech abrogation they attempted. And nobody else ever tried. They'd bluster a bit, but when it came to getting us paperwork, they went away.
