Justice Thomas indicated [1] his severe disapproval of civil forfeiture and interest in invalidating it should a good case present itself, and so it seems that such case just turned up. I'm waiting for the supreme court case with eager anticipation.
Last time there was a potentially suitable case the victim's lawyer made a mistake of not raising the constitutional grounds (4th amendment) during the initial trial, and this formality made it impossible to mount a good appeal.
[1] http://www.slate.com/articles/news_and_politics/politics/201...