Question about Sidewiki

What happens if you buy or sell a site? Do you get all the sidewiki comments too? So if I develop a site, let's say bestwidgetever.com and someone else buys it, but their widget is different than mine so they redo the site, will the sidewiki comments start over? Or are sidewiki comments permanent? There has to be some way for them to reset.

Also, I see this being a huge legal problem for Google. Let's say I'm a big company and I start losing sales because a user is posting comments that are taking away business. I decide I want to sue the user for libel. Now I go to court and get a subpoena for Google to release the user's info. We all know how much great press Google gets anytime they release private information. Posting untrue negative comments on other sites is a free speech issue, but I really think a company would have a case for libel if someone was posting untrue negative comments on a site and drawing away sales to their own site.