The live BJ dealer CAN see you.
I verified this with two sources, (independent Laptop and Desktop security specialists).
Not only see you, but HEAR you also!
Apparently the Live BJ site servers exploit security flaws on the player's computer, allowing for what's called, 'Stealth audio/video non-permissive transmission', or as Symantec engineers call it, 'SAVNPT'.
Even if you don't have a built in mic or webcam they see and hear you by 'tricking' the remote desktop feature built into every Windows and Mac computer.
Micro vibrations, algorithmic analaysis of key-stroke annomolies, static discharge from a flat screen monitor 'reflecting' off the player's face, and what's known as dynamic laser refraction from the computer's mouse (doesn't apply to the older tracball mice) are just a few of the methods they use to make sure you are not playing while taking notes or speaking about the cards to someone who is card counting.

Be very careful when playing Live BJ. Watch what you say out loud and always dress appropriatly.

Comb your hair and try to make the best impression possible, as you may get comped if the Pit Boss sees you are taking his game seriously, and you are clean shaven and well dressed.

Good Luck!