Mike Norton, of Norton Outdoor Advertising, argued that the billboards were not meant to target specific demographics but that it decided to remove them due to the "perception by some that these displays are targeted to specific segments of the population, and are an attempt to intimidate them and suppress their voting rights." (In an e-mail, Norton said "there seems to be no dispute as to the accuracy of the message on the displays.")

A billboard in Northeast Philadelphia directed at Spanish-speaking voters. In English, the billboard reads, "This election, if you've got it, show it." Pennsylvania voters do not need a photo ID in order to vote.

Not all of the complaints are being directed at advertisers and anonymous donors, however. In Pennsylvania, controversy has erupted over a series of billboards that seem to suggest voters need to show their IDs at the polls - despite the fact that the state's controversial voter ID law was recently stayed by the court.

According to the Pennsylvania Department of State (DOS), 58 billboards across Philadelphia and Pittsburgh, as well as a small number in Tioga and Fulton counties, depict a person holding up a photo ID alongside the text "this election, if you've got it, show it." About 12 of these billboards are in Spanish, the DOS told CBSNews.com.

Ron Ruman, a spokesperson for the Pennsyvlania DOS, says the billboards are part of an ongoing education campaign regarding the impending voter ID laws, which, as of now, are slated to go into effect following the November 6 election. He argued the billboards weren't meant to disproportionately target low-income and minority voters but rather that the state is trying to hit the "highest traffic areas we could," which translates into urban areas. According to the recent voter ID ruling, state law does require that voters be asked to show photo ID at the polls, but it doesn't actually require them to present one in order to be able to vote.

While any legal citizen should theoretically be able to get a state-issued photo ID, Lopez and other activists argue that people in low-income communities aren't as likely to have such IDs already - which makes voter ID laws, or the suggestion that IDs will be required at the polling stations, an additional hurdle for voting.

"It's trying to raise the inconvenience factor, and also it's just suggesting that there may be trouble afoot," he said.

Others point out that Pennsylvania was slow to take down some of the old billboards advertising that IDs were a mandate for voting, and argue the government hasn't matched pro-ID law outreach - and that many voters will remain unaware that the law has changed.

Ruman said sending out statewide mailers informing voters that IDs would no longer be required (as had been done to tout the voter ID requirements) was "not a feasible thing to do considering the time frame and the funding," and that the state is attempting to educate voters in other ways. He acknowledged that one billboard touting the ID law remained in place until October 16 - two weeks after the ruling -- though he said most of them were taken down much earlier.