MILWAUKEE â€"  High-ranking members of both political parties were unaware that posting photos of completed ballots on Facebook or Twitter is illegal in Wisconsin, and they promised to quickly take down the posts Friday after election officials reminded voters of the law.

The law bars voters from showing their completed ballots to anyone. The intent is to prevent people from selling their votes and then showing their ballots as proof they voted as requested, Wisconsin Government Accountability Board spokesman Reid Magney said.

But some voters -- including Wisconsin Democratic Party Chairman Mike Tate and St. Croix County Republican Party Chairman Jesse Garza -- were unaware that the posts violated state law. Tate and Garza said they were immediately taking down photos of their absentee ballots.

The warning comes ahead of Wisconsin's heated June 5 recall elections targeting Republican Gov. Scott Walker and five other elected Republicans.

The violation is a Class I felony, punishable by up to 18 months in prison and a $10,000 fine. However, it's unlikely prosecutors would be aggressive about seeking charges.

"We're just pointing this out, that voters are not supposed to be doing this," Magney said. "We're not aware of anyone that's been charged as a result of this."

Walker and the other Republicans facing recall elections were targeted largely because of a law Walker pushed last year that essentially stripped most public workers of their collective bargaining rights. The law prompted tens of thousands of people to protest at the state Capitol.

Tate posted a photo Wednesday showing an absentee ballot marked for two Democrats -- Milwaukee Mayor Tom Barrett, who is challenging Walker, and Madison firefighter Mahlon Mitchell, who is running against Republican Lt. Gov. Rebecca Kleefisch. Four state senators also are facing recall elections.

The caption read: "May have never been more proud of a vote than casting my ballot this am. For everyone who marched, canvassed, called and collected signatures; here is to you."

Tate told The Associated Press he posted the picture because he was proud to support Barrett and Mitchell. When told of the GAB's warning, he said he wasn't aware of the law.

"If that's the law I absolutely will take it down," he said. "And I'll encourage anyone else who's done so to take theirs down."

A similar picture showing Republican votes was posted Tuesday on Garza's Facebook page with the caption: "I just voted absentee. One vote for Walker and Kleefisch in the bank, 1.2 million to go!"

Garza also said he didn't intend to break any laws. He called the GAB warning "a good cautionary tale," but added that voters should have the right to show support for their candidates.

"I think they should revisit the law," he told AP. "I removed mine, and I know others removed theirs, but I should have the right to state who I support."

Dane County District Attorney Ismael Ozanne said he couldn't immediately say whether he would charge voters who violated the law. He said he'd have to consider whether the post was meant to influence others, or if it were being used in connection with a vote-buying scheme.

"We'd obviously have to take a look at the facts," he said. "I guess you'd have to look at how the material was being used, what information was in the posting. But I'm not aware that anyone has been charged for that. This is the first I'm hearing of it."