UPC, Vodafone, O2 and Eircom have pleaded guilty to breaching the Data Protection laws.
The charges related to the making of unsolicited marketing phone calls and sending unsolicited marketing messages.
The companies were ordered to pay almost €15,000 in fines between them.
UPC was convicted of the largest number of offences and received the biggest fine.
Read more RTÉ. Irish Times also covers today’s developments.