Over 12 kilometres worth of telephone wire has been stolen in the south Monaghan area in the past six months.
Eir says more than 1,000 people living in rural parts of Monaghan and east Louth have been impacted by the thefts.
The network provider says the theft of telecommunications cables and copper wire has left homes without telephone and broadband connections, as well as losing emergency alert systems.
Barry Doyle, a local open eir field technician says people must be vigilant because it's being done under the guise of legitamate workers.