They're called super PACs, and these groups can now accept unlimited amounts of cash from corporations, labor unions and people. They can also spend whatever they want to sway voters for or against candidates. Money raised is most often spent buying air time.

"They're using millions of dollars to place ads," said Liz Bartolomeo of the Sunlight Foundation, a nonpartisan government watchdog group.

A 2010 Supreme Court decision paved the way for the creation of super PACs, allowing money to flow freely into and out of these groups. Before the ruling, corporations and labor unions were prohibited from contributing to PACs. Individuals could give a maximum of $5,000.

The more than 100 registered super PACs includes "Restore our Future," a Republican-based group backing the party's presidential hopeful Mitt Romney. It tops the list of the richest super PACs, raising a whopping $89 million this election cycle.

"American Crossroads," another Republican group, is second at $47 million.

The ranking super PAC on the Democratic side, "Priorities USA Action," rounds out the top three at $25 million.

"The Democrats have not had the same success raising money," said John Dunbar of the Center for Public Integrity, a nonpartisan, nonprofit news organization.

Political analysts contend that's because Republicans have been more active players of the super PAC game.

But both sides are blanketing the airwaves with little rules and a lot of controversy.

"The biggest thing about super PACs is you don't know right away who's behind them," said Bartolomeo, who added that the money super PACs receive may be spent however the group wants, including paying for staff salaries

"Every ad that you see you should not take at face value," Dunbar said. "I think you should question it."

The Sunlight Foundation has a mobile app called Ad Hawk to find out more about ads. It allows iPhone and Android users to get more information about the sponsor of an ad by activating the app when they hear a political commercial on TV or the radio.