Any HDMI splitter. The "Content Protection" encryption on the wire for the digital video doesn't allow the stream to be split; to do so requires stripping off the encryption in a way not licensed by the industry consortium.
I'm pretty sure compliant splitters are expected to decrypt, split, then reencrypt. What a waste of resources.
Nah, it's okay to split an HDCP encrypted stream as long as you enforce HDCP on the outputs as well.
I think the standard allows for something like 32 endpoints.
Aren't there non-HDCP splitters around that only allow unprotected content through? (I don't know, but I had thought so)