I suggest taking this with a grain of salt and waiting for a report from others, but:

St. Louis and Missouri Democrat sheriffs and top prosecutors are planning to go after anyone who makes false statements against Obama during his campaign... St. Louis City Circuit Attorney Jennifer Joyce and St. Louis County Circuit Attorney Bob McCulloch are threatening to bring [criminal] libel charges against those who speak out falsely against Barack Obama...

Those officials apparently said what they said under the direction of or with the input of the BHO campaign. More on that as it develops.

UPDATE: It's been confirmed, as Missouri governor Matt Blunt has issued a "Statement on Obama Campaign's Abusive Use of Missouri Law Enforcement" (link):

St. Louis County Circuit Attorney Bob McCulloch, St. Louis City Circuit Attorney Jennifer Joyce, Jefferson County Sheriff Glenn Boyer, and Obama and the leader of his Missouri campaign Senator Claire McCaskill have attached the stench of police state tactics to the Obama-Biden campaign... ...Enlisting Missouri law enforcement to intimidate people and kill free debate is reminiscent of the Sedition Acts - not a free society.

UPDATE 2: Joyce pretends it has "never been or never will be about prosecuting people" (link). Someone apparently spoke with McCulloch, who used the false pro-BHO spin on the kindergarten sex education story as an example of something he'd take action against (link). McCulloch admitted not having read the bill in question.