Credit to: USA TODAY NETWORK , USA TODAYPublished 1:34 p.m. ET July 3, 2018 | Updated 6:10 p.m. ET July 3, 2018

With an estimate of nearly 47 million Americans traveling more than 50 miles during the July 4th holiday this year per AAA, the U.S. Secret Service is warning drivers not to get ripped off by thieves at gas pumps. Veuer’s Maria Mercedes Galuppo has more. Buzz60

Motorists about to pay at gas pumps ahead of the July 4 holiday should ask themselves a question, the Secret Service says: Could I get defrauded?

The agency announced an effort targeting credit card “skimmers” hidden at fuel pumps to steal financial information — and finances — from unsuspecting motorists. The initiative, unfolding this week ahead of Independence Day travels, has agents inspecting pumps in 21 states.

“The Secret Service is leading the charge to protect the U.S. consumer against this growing cyber-enabled financial crime,” the agency said Tuesday in a statement, reporting a Memorial Day effort last month that turned up over 70 such skimmers.

Skimmers are small, electronic devices installed secretly at pumps and able to capture a swiped payment card’s protected data, the agency said. Commercial keys purchased online let fraudsters access pumps often left unattended, according to a report from ABC News.

Thieves then return later to retrieve the devices or transmit it remotely via Bluetooth, before using the information to make purchases, Matthew O’Neil, a representative of the agency, told the network.