The Metropolitan Transportation Authority is trying to make it harder for subway swipe scammers to pull off their crime.

The agency has rolled out a secret pilot program targeting swipe scammers who siphon millions of dollars from the system each year.

The program increases the time between swipes of unlimited cards at the same station from 18 minutes to up to 60 minutes.

The longer the wait, the less profitable the scam is.

The change was implemented at 28 stations where selling swipes is most prevalent.

Scammers force riders to participate by damaging the MetroCard vending machine, then charging riders a dollar to swipe them through the turnstile.