Posterous silently changes external links on users' posts /via Alexey Shamrin
... Instead of
http://www.google.comyou'll gethttp://api.viglink.com/api/click?key=8eb8c964d427e97a1567cec6532655f0......Aha! Posterous is using third-party service here - VigLink. I haven't heard of it before (even Hacker News is now silent about it).
Oh, that is interesting... please read Sachins comment also, as an official statement from posterous.