Devon and Cornwall police are warning local people not to use illegal taxi services which advertise on social media sites.
They say there's been a surge in unlicensed taxis offering cheap rates.
The police say registered taxis and their drivers go through stringent checks - but there's no guarantee an unauthorised cabbie is even legally allowed to drive.
And if there's an accident involving an unlicensed cab, the passenger won't be protected by insurance.
Plymouth child rapist jailed for 12 years
Extra police for sold-out Devon derby
Torquay projects battle for £20m handout
Shock after adult device found at family event
Halted Devon development resumes building
£22.7 million investment in North Devon Hospital
