Donegal Gardai are appealing to the public not to share information on social media about Garda checkpoints and speed van locations.
A spokesman said people mistakenly think they are helping their neighbours and friends by alerting them to such road stops.
However, they are actually arming criminals with ways of escaping detection, they say.
Garda Sean Sweeney made the appeal saying there is a high volume of information sharing on social media in Donegal around these checkpoints.
He said “It’s become very common to share online but this is damaging. Checkpoints are set up for a reason.
“People may get credit for alerting others to such checkpoints but the reality is that these people could be alerting criminals.
“We gain valuable information from checkpoints on the movements of people. While criminals may not be coming from a crime they could be checking one out.
“But, of course, they could also be coming from a crime where they have broken into the home of an older person and by posting information online then people are unknowingly helping these people to escape down a back road.
“We would ask people not to share this information online and if you are considering posting it online then think of the possible consequences if there has been a crime committed in your area,” he said.