The first two shareholder lawsuits were filed Tuesday in federal court in Chicago after the markets closed, seeking class-action status for people who bought stock before the company restated fourth-quarter financial results on Friday.
Perhaps those people should have been reading Hacker News:
http://www.hnsearch.com/search#request/all&q=groupon&...
(The first post is rather long and fairly neutral, but check out some of the posts (and their dates) right after that.)