Michael Mikkelsen, a 29-year-old political activist from Kansas City, Mo., doesn’t support drunken driving. But he’s strongly against police DUI checkpoints, which he says violate drivers’ constitutional rights.

Mikkelson’s taken his mission to Twitter, tweeting out checkpoint locations and getting tips from other Twitter users about checkpoint spots. Sometimes he tweets out the link to a live stream he sets up to monitor checkpoints.

Mikkelsen, who has more than 400 followers, is one of several local Twitter users monitoring police, fire and emergency service activities online.

Other local Twitter users, such as @KansasScanner and @Operation100, send out frequent Twitter updates from what they overhear on emergency dispatch scanners; everything from auto accidents to fires to police chases.

“It keeps the community informed,” said Mike Frizzell, known in the Twitter sphere as @Operation100. Frizzell, 25, has been listening to police scanners since he was 13.

“I’ve always been fascinated by it,” said Frizzell, who has more than 1,500 followers.

At his home in Shawnee, Frizzell has six scanners, which he uses to monitor several area counties. The hobby has also turned into a full-time job, as he contracts with several news organizations, including the Journal-World, providing information about accidents, fires and crime incidents overnight.

Twitter users such as Frizzell can fill the gaps between what happens on the street and what ends up on the news, but it’s important to note that the information is preliminary and not always accurate, said University of Missouri professor Jen Reeves.

Reeves cited an incident in Columbia, Mo., where a Twitter user sent out an erroneous tweet that there was a gunman loose on the Missouri campus.

That’s why news outlets must keep up, she said.

“It’s our job (as journalists) to be prominent enough (on Twitter) to say ‘slow down,'” Reeves said.

Johnson County Sheriff’s Office Deputy Tom Erickson said his office hasn’t run into any problems with Twitter users who monitor the scanners. In the cases where a suspect might gain an advantage by hearing what’s on the scanner, police have several secure channels to switch to, he said.

The Johnson County Sheriff’s Office may also begin sending out their own tweets about emergency calls, similar to what some other larger law enforcement agencies, such as the Wichita Police Department, are already doing.