GOWANUS — This scofflaw got a taste of sidewalk justice.

Vandals lashed out at a driver who parked his car illegally on a Brooklyn sidewalk, spray painting "I'm stupid" on the rear of the vehicle and deflating all four of its tires, according to a police report.

The incident happened earlier this month on Baltic Street between Third and Fourth avenues, where cars have long clogged sidewalks, to the dismay of locals. The city's 311 records show seven calls in the last year about illegally parked cars blocking either driveways or the sidewalk on the block.

The 26-year-old driver parked his 1986 Chevrolet on the sidewalk on Feb. 13 at 8 a.m. while he was working nearby, according to a police report. He returned to the vehicle at 12:45 p.m. and found a picture of a penis spray painted on the hood.

"Do not park here" was painted on the passenger side door, and "I'm a scum bag" was scrawled on the driver's side door, according to the report.

Sidewalk parking has been a chronic problem on the block for years, said street safety advocate Doug Gordon, who lived on the block in 2012 but has since moved away.

He chronicled the nuisance — and he and his neighbors' fruitless quest to get it addressed — on his blog.

Back then Gordon was frustrated by a lack of police response to the problem, but he said Thursday that's no longer an issue. Police from the 78th Precinct are now "very responsive" and crack down on sidewalk parkers when residents point out the problem, Gordon said.

Gordon even tweeted a thank you to local police recently, who responded that they've been "working hard" on the problem.

Big thanks to @NYPD78Pct for sidewalk parking crackdown. Change has been noticeable in last two months. #VisionZero — Brooklyn Spoke (@BrooklynSpoke) February 12, 2016

The NYPD's recent attention to the problem makes the vandalism all the more shocking, Gordon said. The angry graffiti artist probably would have had better luck getting the illegal parking taken care of by contacting the 78th Precinct, Gordon said.

"I don't have any sympathy for someone who parks on the sidewalk and gets a ticket or towed, because it’s illegal," Gordon said. "But I don't think citizens should become vigilantes. It's just wrong, period."