Over 1,500 households in Cavan and Monaghan have been impacted by telephone cable thefts since last August.
In the past six months there have been 66 reports of cable thefts across Ireland, with the vast majority of them taking place in Cavan, Monaghan, Louth and Meath.
Eir estimates that this is the equivalent of 12 kilometres of cable being tampered with.
Gardai believe the cable is being targeted for its valuable copper wire, with the outer cases often dumped on private land.
Crime Prevention Officer in the Cavan Monaghan Garda Division Sergeant Mick Duffy says these thefts can leave vulnerable people isolated for days.