Microsoft as a virus distributor?

Reading today's newspaper I noticed a small article about Chinese computer users who are angry with Microsoft. What's new you might think? Well the case is that Microsoft has developed a Windows Genuine Advantage application that is automatically installed through Windows updates. The program detects whether or not you have a legal version of the Windows OS. If not, the user gets a black wallpaper every hour, during 45 days. You may change it to a wallpaper you like more, but it will be replaced by the black wallpaper in the next hour. This type of computer behavior reminds me of a typical, rather innocent category of computer viruses. It's Microsoft's way to strive against illegal use of their OS. On the one hand they may be right to protect their legal rights, on the other hand it is questionable whether they have the right to infect millions of computer users this way. It seems like taking the law into their own hands, instead of sending out legal claims. Trying to imagine how this would be in a more physical metaphor I can think of a situation that a manufacturer would come into my house to shut down my cd player, so I cannot play copies of CD's anymore. How would that look like? You cannot pop into somebody's home and do things that you believe are right, it would be considered trespassing. Is the Microsoft example a case of digital trespassing?