I'm doing some research about Contributor Licensing Agreements (CLAs) and I was wondering if they are not an overkill. I will probably end up using them in the project I work with because I prefer to be safe than sorry, but I would like to know about examples of projects that have had any kind of legal problem with contributors claiming rights over their contribution.
Vaguely related because Apache contributors are under a CLA, a long time ago there was some feud between JBoss and Apache Geronimo, ... a very long time ago...http://www.theserverside.com/news/thread.tss?thread_id=22337
But these are very rare events and IMHO a CLA is a strong deterrent to contributions. As an anecdote, I was asked once by Google to submit a CLA for a 2 characters documentation typo patch: that was quite ridiculous.
Avoid a CLA if you can. Some licenses such as Apache 2.0 have the CLA baked in.
Or use a simpler approach like Linux and http://developercertificate.org/
No need for a complex CLA process in most cases.