THEY take passengers over the border from Thailand into Malaysia and back without the necessary permits.
Now these pirate Thai taxi drivers have to pay for it, reported Malaysian newspapers.
In a week-long operation by Perlis' Road Transport Department, more than 100 vehicles travelling the route from Satun, Thailand, to Wang Kelian, Perlis, were checked.
Some 22 Thai-registered vehicles were fined RM200 ($87) on the first day of the sting operation which saw 48 officials on duty.
The department is targeting motorists who misuse the required International Circulation Permit (ICP).
So seriously did the department take the operation that its own director Zahari Awang Senik even took part in the sting.
Thai vehicles that travel more than 2km from the border must obtain an ICP at the immigration checkpoint. This permit is issued free of charge.
Some Thai vans and taxis have operated as far as Penang, Alor Star and Johor Baru.
Mr Zahari warned Malaysians not to take illegal public transport into Thailand to avoid problems with insurance claims in the event of an accident.