Police believe most riders agree with Hudson. And though no injuries have been reported, they also insist the showmanship is a safety issue.
"If the dancers make a mistake, someone could get hurt," said Chief Joseph Fox, head of the NYPD's Transit Bureau. "The dancers themselves could get hurt."
Police have responded by studying passenger complaints to determine when and where to put plainclothes officers on trains to nab acrobats.
The arrests are usually uneventful but can turn nasty. An acrobat who was being arrested spit on one officer and tried to bite another.
"No matter how you look at it, it's dangerous," Fox said. "It's dangerous for us, too."
Two decades ago during Bratton's previous stint as commissioner, his "broken windows" crackdowns targeted public drinking, panhandling and most notably the squeegee men who sprang out at intersections to wash the windshields. This time, the department has targeted illegal motorcycles, graffiti — and the acrobats.
Andrew "Goofy" Saunders and some friends started doing routines on trains in 2007, hoping to make $10 to enter a dance competition. Seven years later, the group — W.A.F.F.L.E., for We Are Family For Life Entertainment — has a shoe-brand sponsor and has been booked for music videos, parties, even a wedding.
"We're not just knuckleheads. ... We're actually about something," said Saunders, 20.
But the roughly 12-person troupe has largely stopped performing on subways because of the police attention. Members now hope to line up a public space to flip with permission.
"There's no reason for being locked up for doing what you love," Saunders said.
Reach Jennifer Peltz on Twitter @jennpeltz and Tom Hays @APtomhays