A small sample of Locast’s program guide for Phoenix viewers.

Internet customers in Phoenix and Atlanta can now watch local, over the air TV stations for free thanks to Locast, a not-for-profit streaming TV service that is fighting the escalating costs of online streaming of network and local television programs.

That brings a total of 15 cities to the Locast roster, and the service has also expanded the number of stations it streams in many of its existing markets to include additional digital sub-channels it neglected previously.

Locast geofences its service, requiring viewers to allow Locast to verify location data proving a viewer is within a Locast service area. That is an effort to comply with current copyright law, which allows Locast to operate as a local relay service. That has not stopped a coalition of TV networks from suing Locast, claiming it violates that copyright law and is only masquerading as a non-profit organization. The lawsuit cites Locast’s increasingly aggressive fundraising messages found on its app and as a pre-roll streaming message each time a viewer switches channels. Some viewers claim the only way to get rid of those messages is to enroll as a donor member and contribute several dollars a month to the service.

Locast says it uses contributions to bolster its legal defense fund and also acquire equipment and resources to launch the service in new cities. Locast officials claim they will eventually launch in all 210 TV markets if contributions are adequate to cover the costs.

Locast carries all major network affiliates, independent and PBS stations, and most ethnic language and general interest sub-channels. Some religious stations are also included, but most home shopping channels and those dedicated to airing paid commercial programming 24/7 are omitted. In Atlanta, Locast carries nearly three dozen local channels. In Phoenix, 40 stations are available.

Locast does not offer time-shifting DVR service or on-demand programming. It relies entirely on live streaming, but offers viewers an on-screen program guide.