http://marc.info/?l=openbsd-tech&m=129236621626462&w=2
Summary: Former OpenBSD engineer claims the FBI paid some engineers to backdoor their IPSec implementation.
It could be some crazy ramblings, or it may have some truth to it.
IPSec is used to secure network links across IP-based networks. It's my understanding that OpenBSD's implementation is widely-used in other products, similar to OpenSSH.
http://en.wikipedia.org/wiki/Openbsd
http://en.wikipedia.org/wiki/Ipsec