ORM + You = Lawsuit
"FireStar recently filed a lawsuit (also in East Texas) against Red Hat for the use of the principle of Object Relational Mapping in Hibernate (developed by JBoss), a popular component of Java applications. Jim Farmer of immagic has confirmed that Sakai uses Hibernate and is, therefore, vulnerable to both direct and indirect infringement charges by FireStar. Farmer has also confirmed that while uPortal 2 does not use Hibernate, plans are underway to incorporate the component in uPortal 3. FireStar's patent claim goes beyond Hibernate, which is only one implementation among many of the Object Relational paradigm. Potentially any web framework that uses ORM, including those deployed in PHP, Ruby on Rails, or .NET, is vulnerable."
[1] http://tatler.typepad.com/nose/2006/08/the_patent_cris.html