WordPress Germany FAQ » Privacy notes on the use of Akismet in Germany. Found at Schockwellenreiter and also implemented - I already had the explanation in the imprint, now the checkbox when commenting has also been added. It might be a bit cumbersome for the three people who comment here from time to time, but I think it's bearable. Especially since there are other ways to comment - your own blog posts, or tweeting, facebooking or googleplussing (there's also a privacy-compliant user consent for that), so you can choose where you want to leave your data traces. (And of course, you can also simply send me an email to the email address listed in the imprint, which then works without consent - but be careful, my email provider is Google! They are evil!)