One of the largest rubbish collection companies in the country is calling for Gardaí to protect its staff.
Greyhound says workers are being attacked in certain areas of Dublin, with some staff suffering injuries.
It says the anti-social behaviour has been a consistent problem.
John Brosnan, Managing Director of the firm, said: "The incident that resulted in a two-year prison sentence involved one of our crew having a broken cheekbone.
"Previous incidents have resulted in crews being threatened by people holding a 4x2 plank of wood and hammers and other instruments that would be quite intimidating."