LEVITTOWN, N.Y. (CBSNewYork) — Police are checking ATMs at 7-Eleven stores across Nassau County over concerns that more bank accounts could be wiped clean.

An alert customer recorded and posted a video when detectives were called to check on a suspicious card reader at a store in Seaford.

READ MORE: Gas Eyed As Cause Of House Explosion That Killed 1 Woman, Injured 8 Others In The Bronx

Police said that was the tip of the iceberg, and officers are now looking into more than 100 7-Eleven locations, CBS2’s Jennifer McLogan reported.

“Yes, a customer told me that the ATM couldn’t read her card. So I went over and I saw that something wasn’t right, and I just called the police,” one manager said.

In Island Park, another planted illegal device was discovered, stealing account numbers and customer information.

“I got a phone call that my card was compromised. And this is the only ATM that I use,” said victim Donald Maccio. “Some gray was attached to this too, it blocked, you couldn’t see. I said, ‘OK what about my money?’ Sorry it’s gone.”

READ MORE: NYPD Officer Released From Hospital After Being Shot In The Bronx

So far, ATMs at multiple 7-Eleven stores on Long Island appeared to have been tampered amid a pattern crime investigation.

“You always have to make sure that the face is always flat and it’s not loose and you check it,” said retired NYPD Lt. Eric Kubelle. “So if it’s sticking out a little, that way you know there is something suspicious with the device, because of course they are putting it on top of that.”

“I don’t use ATMs. That’s the reason I don’t use ATMs, because of scams going on,” said Island Park resident Fred McDonald. “My old boss got $1,400 taken from her twice.”

An alert has gone out for a male suspect, five feet eight inches tall, 180 pounds, wearing a black jacket and baseball cap.

The suspected skimmer caught on video was last spotted in Levittown, having fled the 7-Eleven walking east on Hempstead Turnpike. It’s unclear if he’s part of a larger ring.

MORE NEWS: New York AG: Trump Organization Misled Banks And Tax Officials

Banks are required to make good on most types of losses from personal accounts. If you tell you bank within two days after you learn of a loss or theft, you can lose no more than $50.