It turns out that IBM own a 15-year-old patent for one of the biggest sources of revenue on the internet: Advertising.
Basically speaking, IBM owns a patent for displaying advertising and information on a single web page. This also extends to making the ads relevant to the page, and choosing ads relevant to the location of the viewer.
Apparently, thats 50% of the web. Billions of websites, and every single webmaster could soon owe IBM money.
This could spell trouble for the entire web.
Big trouble.
More info:
http://blogs.zdnet.com/BTL/?p=3848&tag=nl.e622