A good example RE40989 Atomic Operations on Data Structures.
If you read the claims you'll notice they have basically patented the way of 'atomically' changing arbitrary sized data by simply acquiring a mutex (or atomically setting a 'do not touch' flag), making the changes and then removing the flag.
If you want to do parallel programming at all you will have some sort of locking mechanism to prevent multiple threads from writing the same data structure at the same time. And if you do, you are infringing the patent.
P.S. You can all thank me now. You know of this patent so it's 3x penalty for willful infringement ;)