Police spokesman Joel DeSpain said once skimmers are found, they are removed, and owners are encouraged to check their pumps daily. Police will also share photos of what skimmers look like to gas station owners. Officers will be going to each station to “walk employees through what they should be looking for,” DeSpain said.

DATCP spokesman Bill Cosh urged consumers to ask stations about steps they’re taking to secure their pumps. The skimmers, either internal or external, read information off cards without the consumer knowing, so accounts can be hacked.

The FBI and IRS have been conducting local skimming investigations at gas stations and ATMs but haven’t released information about arrests.

Police and IRS agents temporarily shut down several area gas stations several weeks ago, but DeSpain told the State Journal the skimmers found were not from one particular chain or owner.

The investigation by DATCP first found one card skimmer inside a gas pump, which prompted Madison police to encourage other operators to check their pumps, DeSpain said. “Five skimmers were found in all, but we can’t say there might not be others,” DeSpain said.

DATCP said Tuesday that inspectors have recently become aware of skimmers in gas pumps throughout Wisconsin.