NBC is now providing access to live broadcast feeds over the Internet — but only if viewers already subscribe to a cable or satellite TV provider that has a deal with the Comcast-owned programming group, and only if they happen to be in the right part of the U.S.

Initially, NBC’s authenticated 24-hour live-streaming feeds are available via the Peacock’s 10 owned stations, which include those in New York, Los Angeles, Chicago, Philadelphia, Dallas-Fort Worth and the San Francisco Bay Area. NBCU said it is “working with its TV affiliates to offer additional local launches moving forward.”

ABC has launched a similar authenticated service for access to live TV in select markets, on the web and via mobile devices. CBS, meanwhile, this fall introduced a $5.99-per-month subscription service, All Access, that includes livestreaming in 14 U.S. markets.

For NBC, in the present markets, the live TV streams are available to customers of Comcast, DirecTV, Dish Network, Time Warner Cable, Verizon FiOS, AT&T U-verse, Cox Communications, Cablevision Systems’ Optimum TV and others. The livestreams for now are available only on the web; NBC said it expects to launch the service on mobile platforms in early 2015.

The live video feeds include all of NBC’s programming, including local news; “Sunday Night Football”; primetime series like “The Voice” (pictured, above) and “State of Affairs”; and “The Tonight Show Starring Jimmy Fallon.”

Also Tuesday, NBCUniversal announced the launch of a TV Everywhere marketing campaign across its 14 cable networks. The campaign, with the tagline “Watch TV Without the TV,” will run on TV and outdoor media from Dec. 26, 2014, through Jan. 1, 2015. The campaign is aimed at highlighting NBCU brands and apps, including: E! Now; USA Now; NBC Entertainment; NBC News; Bravo Now; CNBC; Esquire Now; Golf Live Extra; MSNBC; NBC Sports Live Extra; Oxygen Now; Sprout Now; Syfy Now; and Telemundo Now.