California is the latest state warning of suspected absentee ballot fraud.

In Bakersfield, Kern County election officials caution voters not to give their absentee ballots to a third party. Officials say they should be mailed in, returned to the Elections Department in person, or turned in at any polling place on Election Day.

A Democratic voter says two young men, maybe teenagers, knocked on her door with what appeared to be a bagful of absentee ballots that hadn't been turned in yet and forcefully requested she turn hers over.

The woman refused, and Chief Deputy Registrar Karen Rhea tells Fox News it is illegal in California for anybody other than a voter to send in an absentee ballot. The case is in the hands of prosecutors now. Officials do not know for whom the canvassers worked, or for which party.

While local election officials, the F.B.I., and the U.S. Attorneys will be on the look-out for possible voter fraud, citizens groups are also active.

In Minnesota, where Democratic Senator Al Franken's controversial 312 vote victory over Republican Norm Coleman in 2008 still echoes with allegations that felons illegally voted, one group is taking voter fraud head on.

Election Integrity Watch has plastered Minneapolis and St. Paul with bus ads and billboards warning about voter fraud and the group is offering $500 rewards for tips that lead to convictions of fraud organizers.

Just this week, local prosecutors charged 47 more people with illegally voting in Minnesota in 2008, and additionally Minnesota Majority President Jeff Davis says they've uncovered 60 more cases of suspected fraud in the current election. Minnesota Majority is one of several groups that have formed the Election Integrity Watch coalition.

"What worries me the most is that honest citizens are being robbed of their votes. That's my big concern," says Davis. "I mean, election integrity is a cornerstone of our Democratic republic. People have fought and died for our freedom to go out and cast a vote and elect officials to represent us in our government."

But some voters groups warn that poll watching by citizen watchdogs could lead to possible voter suppression. The N.Y.U. Brennan Center for Justice fears some citizens could go too far.

"We are worried about voter intimidation, people being aggressive, people confronting voters directly, people hovering over them following them around in intimidating ways," cautions the Brennan Center's Wendy Weiser. "That's certainly something that has been a problem in the past and we are worried about that this year. Discrimination is another concern."

But Davis counters that "we're asking people to be mindful, watchful of what things to look for. Record the details. Immediately report any suspicious activity that they see, but not to directly confront voters."

"Our mission," he says, "is to ensure fair and honest elections. We've concluded that it's up to us, 'we the people,' to ensure the integrity of elections... I think the only people who should feel intimidated by what we're doing are those people intent on committing voter fraud."

If you suspect voter fraud where you live, tell us. Our email address is Voterfraud@Foxnews.com. We have received many e-mails from across the country dealing with absentee ballot issues. Some people tell us they have not received the ballots, some say multiple ballots are mailed to their homes, and others say they receive absentee ballots addressed to people who they don't even know.