[FooBarWidget]

Never heard about it happening to a BSD licensed project, but it has certainly happened to GPL licensed projects. Some years ago there was a company who rebranded a GPL'ed CD ripping program, removed all author credits and sold it without source. The authors eventually found out through disassembly.

[RexRollman]

I think there was a company doing that with a PowerPC emulator some years ago. A hacker called them out on it.

EDIT: CherryOS

http://en.wikipedia.org/wiki/CherryOS