The hostile takeover bid for Digital Impact got a little more hostile, with the online direct marketing firm suing its spurned suitor, infoUSA, for alleged patent infringement, according to DM News. A Digital Impact executive said that the firm first brought up the patent issue with infoUSA in the middle of 2003. The patent suit was filed three days ago, the same day Digital Impact rejected infoUSA's $2 per share offer to acquire the company.