Clam, what makes you think TV uses low power unlicensed transmitters? UHF translators been around long before the cable network as we know it today even existed and they're licensed to the broadcast station, ERP is 1KW as it is with all LPTV stations. "Low power" is a comparative term, a kilowatt is high power to a ham but low power to the broadcast industry. So far there haven't been any cable ingress problems due to their placement so I don't expect any in the future.
Ingress has always been a problem with public service, commercial and ham transmitters on cable channels; cable uses the same frequencies and there are no restrictions on transmitter or cable placement but that's a horse of a different color entirely. Bottom line is it's up to the cable company bound by federal law to prevent signal egress causing interference to on air services as you probably know but they're also bound to provide adequate service to the customer.
Leaks cause problems they just don't need, ask Larry. (;->)
FYI, the OTA pickup at the head end(s) hardly receive weak signals. Those antennas are single channel monsters on towers feeding receivers through hard line and are located in the primary coverage area of the broadcasters. It's rather like you putting up a 100' tower and the biggest baddest antenna you can lay your hands on when rabbit ears will do. Many cable systems' service blocks provide OTA service from more than one market and have multiple head ends, you can only shove RF down so many miles of coax and employ so many repeaters before the signal quality degrades to the point of being unusable.
I hope that clarified things a bit for you guys so relax Alfred, what me worry?