That is the answer. Never heard of a parking barnacle? Allow me to fill you in. Introduced in 2016, barnacles are used to combat illegal parking and are made by an American company called Barnacle.

People who owe parking ticket fees at the University of Regina may now find "Barnacles" on their vehicles' windshields. Barnacle is the trade name of a device that can be attached to a ticketed ...

The City of Columbia has brought back the use of yellow Barnacles for vehicles with unpaid tickets. According to Columbia ...

More information: Niklas Dreyer et al, Phylogenomics of enigmatic crustacean y-larvae reveals multiple origins of parasitism in barnacles, Current Biology (2025). DOI: 10.1016/j.cub.2025.06.007 ...