We work on a lot of these cases, almost always on the management side. Here's a few examples...
Wasted Time
In an EEOC suit, plaintiff complained that she was constructively terminated since she was given an impossible volume of work to complete. Electronic legal was asked to examine her computer by management's attorney.
We found that she visited an average of 360 web pages a week, and spent two to three hours a day playing fantasy football. We even built a nice set of graphs to illustrate her web wanderings.
Pornography
Surfing pornography is generally against the corporate computer usage rules, so when porn is suspected, we are often asked to investigate and report. It is usually very simple to find.
Stolen Clients and Information
We seem to get a lot of cases involving principles or employees quitting and starting competing businesses. One of our favorites was finding defendant's business plan left behind on his old computer. Not only did the plan clearly identify going into competition with his then-current employer, it even identified exactly how much business he could take with him from his employer's client base. By the way, the technology in recovering this plan included data carving, one of those dark-magic forensic techniques that finds files buried within other files.