Quite a few of the games companies are now installing a software checking system on your PC without your knowledge and particularly without your consent. This makes sure that you don’t make or try to run illegal copies of the game. In many cases this software doesn’t appear in the add/remove programs panel and can’t be easily uninstalled. It also runs all of the time on your system not just when you start your legitimate version of the game. Which leads people to brand it, quite rightly, as spyware.
Personally I don’t believe piracy will ever be gotten rid of (there is too much money to be made). This is another pathetic, ham fisted attempt to clean up the situation which only serves to annoy legitimate owners.
I have no idea why it’s limited to 5 installations. It’s rather stupid and will cause no end of legal wranglings.
Spore is another game which has this DRM system in place.