Men who have a habit of looking up women's skirts should be watching for something else: a City Councilman is proposing to make peeping a crime.

Voyeurism is already illegal when the subject is unaware and the image is recorded on camera, but as the law stands now, New Yorkers are still free to look as much as they want.

Councilman Peter Vallone Jr. introduced legislation Wednesday that would make peeping a misdemeanor, punishable by a maximum of 90 days in jail and $500 fine.

"These perverts use their eyes to invade the privacy of people's bodies, leaving many feeling violated," he said.

Vallone said the legislation was inspired by an incident at the subway stop near his district office in Queens. Several female constituents had complained to him about a man that routinely stands under the stairwell to the elevated stop, only on warm days in the morning, and appears to be peering up women's skirts.

The New York Civil Liberties Union said Vallone was going too far with the bill.

"It raises major Constitutional concerns because it defines voyeurism in vague and overly broad terms that would give police officers broad latitude to arrest New Yorkers guilty of nothing more than a furtive glance," executive director Donna Lieberman said.

Vallone says that to be arrested for peeping, the person would have to be observed repeatedly positioning himself to view another person's "intimate parts" that otherwise would not be visible to the public.

One could also be arrested for spying on someone who has a reasonable expectation of privacy, like a person undressing in an apartment. That element may be difficult to enforce.

"New Yorkers look into each other's apartments all the time — we're living right on top of each other," Lieberman said.

The councilman's staff acknowledges that there are a number of gray areas that need more attention as the bill goes through the hearing process.

Video voyeurism is a felony punishable by up to seven years in state prison.