This doesn't make much sense -- other audio/video sharing systems (GTalk / etc) would experience the same problem then.

I believe you are referring to the one-party / all-party telephone recording laws, where in some states all parties to the call must know the call is being recorded. This is not relevant for this software program (unless it is being used to stream audio from a phone call...)

But the "hosting" party must click Accept to begin recording, thus they'd know they themselves were being recorded. In addition, at this point, the onus is on the recorder (as they were likely instructed in the Terms of Service they accepted), not the app, to ensure that the folks they're recording agree to be on camera/recorded.