The National Association of Broadcasters sued the Federal Communications Commission (FCC) on Monday to block the commission’s order requiring TV stations to put political advertising data online.

In their filing with the U.S. Court of Appeals for the District of Columbia, the broadcasters said that the FCC overstepped its authority and that the rule is “arbitrary and capricious.” They also said the requirement infringes on their First Amendment free-speech rights.

An FCC spokesman said the agency would defend the regulation in court.

{mosads}“The public file rules are a common-sense update by the FCC to move from paper to online access to public information in the digital age,” the spokesman said. “The rules are consistent with Congress’s directive to ensure public availability while providing cost-savings for broadcasters.“

TV stations were already required to compile data on how much political campaigns paid for advertisements, but the rule will require the stations to load that information into an online database on the FCC’s website.

Previously, anyone who wanted access to the information would have to go to the TV station in person.

For the first two years, the rule only applies to network-affiliated stations in the top 50 markets, but after that, all stations will have to comply with the requirements.

The FCC says the rule is part of its effort to put more information online, and watchdog groups hope the rule will shed light on the big money behind political ad campaigns by making the data more accessible. The 2012 election is expected to see an influx of spending from outside groups such as super-PACs.

Corie Wright, senior policy counsel for media activist group Free Press, said the lawsuit against the rule is nothing more than an attempt to “stall an important and overdue transparency initiative.” 

“The FCC decision to put the political files online will bring broadcasters into the 21st century, and will make already public information more easily accessible to everyone,” Wright said. “The FCC made the right decision and is on firm legal ground.”

But broadcasters say the regulations are burdensome and argue it is unfair to impose requirements on broadcast television that don’t apply to its competitors in cable and satellite. 

The FCC approved the rule last month in a two to one vote, with both Democratic commissioners voting for it and the sole Republican dissenting. 

Robert McDowell, the Republican commissioner, worried that the rule would force broadcasters to reveal sensitive pricing information. 

“If the concern is to know where campaign money is going, the public interest might be better served if Congress were to focus its scrutiny on the spenders of campaign dollars rather than just one of many, many, many recipients,” McDowell said, noting that campaign money also flows to radio stations, cable channels, newspapers and websites.