MTV.com reports that the department has opened an investigation after the "Disturbia" singer tattooed some of the tattoo artists at East Side Ink tattoo parlor on Wednesday night.

Seems it's a no-no for an untrained layperson to just go around injecting others with ink, so the department sent someone down to the parlor to do some sniffing around.

"Only licensed tattoo artists can administer tattoos in the city according to the City's Health Code," a statement from the department reads. "We are sending someone to follow up on this."

Should the city decide to pursue the case, Rihanna could face three misdemeanors , with fines ranging from $300 to $1,000. (We're guessing she'll be able to cover it.)

East Side Ink owner Yadira says that the Bahamian songbird didn't intend to go on a tattooing spree when she entered the parlor. (Along with her own tattooist BangBang, she reportedly inked up two others.) She apparently came in for "a few hours, just hanging out and joking," when BangBang suggested that she fire up the tattoo gun.

"We had a blast," Yadira noted. "It was so funny and cute."

Have your say in the comments section: Do you think the city is making a big deal out of nothing?