A new privacy concern springs from a simple technical fact: Almost all cellphones have a GPS feature that can give the phone’s location to within about 50 feet.

While the feature’s purpose is to link the phone to the nearest relay tower, it can also be used by others – including law enforcement agencies – to track the phone’s users wherever they go.

That has led the American Civil Liberties Union to raise concerns that police may be tracking people without proper cause. So, the ACLU has asked its affiliates in 31 states, including Maine, to use right-to-know laws to see if documentation exists showing such abuses.

Police say that they only use the capability infrequently and after seeking the proper warrants, and in Maine they complain that the right-to-know requests are unreasonably broad and difficult to accommodate.

They have a point. It’s reasonable to ask for at least minimal evidence of official misconduct before laying a significant financial burden on public agencies in this manner.

That does not, however, mean the ACLU’s concerns are unfounded. The proper way to approach the issue would be to pass a law making it clearly illegal for police to use phones’ GPS without due cause.