Kate Carrara is the Buttercream "cupcake lady," selling frosted goodies from a converted postal truck to lines of devoted fans in Philadelphia.

On Tuesday, she posted some bad news on her Twitter account, which has more than 4,000 followers.

"Sorry everybody, L&I confiscated the truck due to map disputes. Hopefully we can straighten it out or else we may just sell cakes from jail," Carrara wrote.

Then came the Twitter outrage, one day after the city was ridiculed on the Internet for trying to collect fees - or taxes, depending on your outlook - from bloggers.

"Another great example of how business unfriendly the city is," a follower commented.

"Does the city just hate cupcakes?" asked another.

"Fight the power!" someone urged.

Maura Kennedy, a spokeswoman for Mayor Nutter, pinned the blame on the Philadelphia Parking Authority.

Parking Authority spokeswoman Linda Miller said her agency knew nothing.

It was indeed the city's Department of Licenses and Inspections. Carrara provided a copy of L&I's "Report of Removal," with the violation described as "Vending in a prohibited area."

She was parked on Market Street near 33d in University City and had a line of people waiting for cupcakes, but had yet to start selling.

She said she had run-ins with L&I before and hoped that where she was parked was all right.

She said three officials from L&I's Business Compliance Unit drove up to her truck around noon and blocked her from leaving.

One of the officials then drove off with her truck, she said.

"Don't worry, I'm a very good driver," the man said, Carrara recalled. "I've done this before."

They left her to walk home, she said. Her husband went to L&I, paid $200 to get the truck back, and was told to retrieve it at what appeared to be a private garage in South Philadelphia.

Carrara, 35, said she would avoid University City for now. She complained that the rules for where she can park are murky and plans to ask City Council for some kind of regulatory reform.

Until then, the truck is back in business and scheduled to be at JFK Plaza at 10 a.m. Wednesday.