A bad thing: The new version of Internet Explorer that came with Windows XP.
Specifically, the added inability to View Source on online webpages. I mean, how much does that suck? The HTML, Javascript, whatever, is actually already in my computer, generating the page I see, but my own mutinous software won't allow me to see that code simply because I got it from someone else. I mean, I would never have learned HTML if I hadn't been able to steal bits and pieces from other people's websites. Stealing code is what the Internet's all about. I think this is a clear sign that the current frenzy over copyright protection has gone entirely too far.