They didn't block communications in Journey to Babel, they located the transmitter with a locator. Thelev was able to speak to the other ship, until they caught him. They didn't even know he had a transmitter until his antenna broke. But then, if hand communicators wouldn't work because of M-5 blocking all frequencies, I'm back to the first course, that M-5's total control of the ship was just that, total, and no amount of jibberjabber that the surviving 19 man crew could stop it, but no one outside of those 19 would have thought or guessed it. A really bad analogy would be like the Enterprise was a mad dog, and whether it was abuse or rabies that caused the behavior, it has to be stopped. Kirk crazy, he'll show'em, or M-5 out of control and killing, it's really irrelevant who's pulling the trigger. Maybe Chekov seized his chance with only 19 other guys to beat and take over and rule the galaxy as Czar Pavel I. Actually, the person who wanted to "show'em" is really Daystrom, Daystrom the one who imprinted his engrams into M-5, which inherited his crazy. You don't expect your toaster to go rouge and assault you, unless you live in Maximum Overdrive. I'm being more silly today, but still my point... I thought I had a point.