IT teams at law enforcement agencies across the United States have been dealing with an unusual challenge. White collar criminals, mostly based in foreign countries, have begun targeting police departments with “ransomware”—software that infects a computer and overwrites data, making a system inaccessible unless the user pays a ransom via Bitcoin.

The problem mainly targets smaller police departments. Some of the attacks that have been confirmed on the record occurred in places like Tewksbury, Massachusetts, and Midlothian, Illinois. Criminals behind the attack tend to look for police departments in small communities with limited resources—in other words, organizations that typically don’t have sophisticated IT teams or extensive security measures. Ransom amounts are usually modest, and hover around $500, Route Fifty reports.