The Irish Council for Civil Liberties (ICCL) is urging Ireland's MEPs to support European Parliament moves to safeguard the privacy of people's e-mail, telephone and fax communications.
The organisation has written to all 15 Irish MEPs asking them to back amendments to a proposed EU directive on telecommunications privacy to be voted on next week.
It warns that the directive, in its present state, allows the "blanket retention" of data, and that this raises serious concerns for civil liberties and the right to privacy.
The directive says member-states can restrict the scope of privacy rights "when such restriction constitutes a necessary measure to safeguard national security, defence, public security, and the prevention, investigation, detection and prosecution of criminal offences".
The ICCL believes this provision is too broad and increases the risk of widespread communications surveillance by European law enforcement agencies.
A number of member-states, including the UK, France, Belgium and Sweden, are already pushing for telecommunications companies to be required to retain all traffic data for at least 12 months.
The ICCL said it could be difficult for Ireland to avoid introducing similar controls given there is a tendency among multinational telecommunications companies to standardise systems across their networks.
"If the directive is passed in its current form," said Mr Malachy Murphy, co-chair of the ICCL, "then all telecommunications users run the risk that details of every call, e-mail, fax or surfing session they carry out will be stored.
"This would constitute a gross infringement of their right to privacy and would effectively mean their every movement in telecommunications networks could be tracked."
Under the directive, law enforcement agencies would not be able to access the content of communications without a warrant.
They would, however, be able to access e-mail addresses; the times and duration of land and mobile phone calls; numbers dialled; the time, size and destination of faxes; URLs (addresses) of websites visited; and the location of Internet newsgroups accessed.
Amendments have been tabled prohibiting "any form of wide-scale or general or exploratory surveillance" and demanding data access be granted only in "entirely exceptional" circumstances.
The Green Party MEP, Ms Patricia McKenna, said: "We want to ensure that people's right to freedom of expression and their right to be considered innocent until proven guilty be enshrined in legislation. So much communication is done by electronic form today that new protections are needed."
Among those supporting the introduction of new safeguards is the European Data Protection Commissioners' Working Party.
The Irish Data Protection Commissioner, Mr Joe Meade, said the introduction of blanket surveillance could be seen as disproportionate. Ultimately, however, he would be required to implement any changes agreed by member-states.