TFS says nothing about contracts, and this is slashdot so you have to assume that people will not RTFA. I blame the summary.
BRG is suing Facebook for theft of trade secrets and breach of contract, among other things, and asks for a jury trial. It’s seeking unspecified financial damages and an injunction to stop anyone using its technique.
It didn't say about signing, but BRG claims that they have established a contract with FB. It could be paper/verbal contract. Who knows at this point?