CBS is threatning  ABC with a lawsuit over s new ABC show that borrows heavily from CBS's 'Big Brother'.

Glass House is a new reality show currently in talks to premire on Abc, and it has the big wigs at Cbs hopping mad.

In Glass House, contestants are stuck in a house, filmed 24/7, and what do you know - eventually voted off one by one. Sound familiar, the folks over at CBS think so.

CBS executives had this to say about the show:

In the strongest possible terms, we must admonish ABC and anyone involved ih the development of 'Glass House' that will be acting at their own peril if they continue to proceed in this manner.

Pretty harsh words from CBS. There are 18 former 'Big Brother' staffers working on the ABC show.