It makes sense if you think you're likely to have to defend the decision in court. For instance, I've worked on a team where a guy was fired for performance rea

It makes sense if you think you're likely to have to defend the decision in court. For instance, I've worked on a team where a guy was fired for performance reasons that were obvious to all of us, but he sued and claimed it was discrimination. HR had known of a performance problem and the process was documented, but if the trustworthiness of the manager who gave them all that information is cast in doubt, could they really defend it quickly and decisively in court? We all had to be deposed. Imagine if it became a lengthy court case. I imagine it would be nice for the company to have a paper trail of convincing evidence of a performance problem. A timeline of significant, non-work web browsing during work hours on work machines would do the trick, and protect the rest of the team and the company. That said, I agree with the commenters that I wouldn't want to work somewhere that did this as a matter of routine. I always have my work laptop encrypted with a key only I know and I have not (yet) been forced to give work root access for management. I'm always confident handing in my laptop that they couldn't find anything even if there was something.