The Federal Election Commission is trying to get some of the country's top super PACs to be more open about where they spent their money — and is getting shrugged off by the super PAC supporting Mitt Romney. 

This year, the normally quiescent FEC dinged six of the nation's top 11 spending super PACs, some multiple times, for not disclosing the states in which they aired political ads during the presidential primary and caucus season, one of the requirements on spending reports related to elections. In response, the super PAC supporting Mitt Romney, Restore Our Future, challenged the FEC's interpretation of the agency's own rule, and asked for a determination from the FEC's office of legal counsel. The other big-spending presidential super PACs backing a presidential candidate have complied with the request by amending their reports or responding with explanations.

The dispute involves ad buys — some in the six figures — that dominated the airwaves during the primaries and caucuses of the GOP presidential nomination contest. Besides Restore Our Future, the six committees are Winning Our Future, which supports former House Speaker Newt Gingrich; Endorse Liberty, backing the presidential campaign of Rep. Ron Paul, R-Texas, Our Destiny PAC, which supported former Utah Gov. Jon Huntsman, Priorities USA Action, backing President Obama's reelection bid, and the Tea Party-affiliated super PAC Freedomworks for America.

At issue for Restore Our Future is an over $400,000 national cable buy on Fox News in February that does not disclose the states it airs in, one of the requirements in primary election ads. The FEC has asked the committees to divide up the total cost of a national buy and allocate it among the states that have yet to hold a primary. Restore Our Future contends that method is not accurate accounting.

The FEC's action followed an advisory opinion it issued in February involving a committee called Western Representation that sought to avoid filing 24- and 48-hour reports for its internet advertising costs, instead wanting to place the costs on monthly reports. The FEC denied the request, saying it should file the daily reports and divy up the costs among the states yet to hold primaries. 

All of this debate over presidential primary spending aside, most of the reports related to the primary did disclose what states they aired in. That won't be the case anymore as the presidential super PACs have pivoted to aim their ads at the general election — a contest that most political observers believe will be fought out in a handful of battleground states. Committees are not required to disclose the states where their ads run if they are related to presidential general election, which is considered by the FEC to be one national election.

For instance, since Santorum and Gingrich have dropped out of the race, Restore Our Future has checked off general election on its forms, leaving no state listed for more than $4 million in spending.

In his response to the FEC, Restore Our Future's treasurer, Charles Spies, wrote that the cable buy criticizing former Sen. Rick Santorum hit every Fox News subscriber. "This arbitrary and burdensome request…is not supported by any reasonable reading of either the statute or the regulations, and will generate inaccurate and meaningless statistics," he wrote. Because of the unique nature of the presidential primaries, with multiple elections in a short period, "it would be extraordinarily  burdensome to attempt to take into account every state's 24/48 hour deadline when dealing with a national buy," Spies wrote, a reference to the FEC's requirement that ad buy information be posted within 24 hours if made 20 days or less before an election and within 48 hours if the ad is purchased outside that window.

Other super PACs decided to handle it differently. The Internet buy in question for Priorities USA Action cost $15,000. So, as per the FEC guidance, if that's divided by 50 states, it did not meet the minimum reporting threshold for each state, its treasurer Greg Speed wrote the FEC.

Winning Our Future made a nearly $900,000 national radio and email buy in February praising Gingrich and criticizing Romney without disclosing any states it played in. The pro-Gingrich PAC said that was consistent with advice it got from the FEC's compliance division. But, to make amends after being slapped with the letter, the group filed 63 pages of reports dividing the buy among different states.

Endorse Liberty buys mostly Internet ads, which run nationally on platforms like Facebook and Google. The committee did not disclose any state in their intitial reports in January. After the letter, it simply decided to pick the state where the primary would be held next because that's what they felt like their aim was "in their hearts," said the PAC's assistant treasurer, Dan Backer.

But Backer, who has an active law practice filing cases that challenge campaign finance regulations,  says the FEC is wrong and said he would to sue the agency over a similar issue in the coming weeks.

That lawsuit, on behalf of another client, Western Representation PAC, argues that the FEC infringed on the group's constitutional free speech rights by requiring disclosure of the costs of Facebook ads the PAC purchased.  The cost of the Facebook ad changes daily, and as primaries pass, the amount spent on ads has to be recalculated over and over. Backer says this is unconstitutionally burdensome.

The FEC had recommended, in an advisory opinion in February, that Western Representation assign advertising costs to states by dividing the total it spends by the number of states yet to hold primaries. Backer calls that a "ridiculous, artificial chopping up process."