On the same day the French legal press association (APJ) announced that it would appeal to the ECHR to strike down the sweeping powers the law gives to intelligence agencies.
The law, which won the support of 80 per cent of France's MPs and has been cleared by the Constitutional Council, allows large-scale surveillance not only in terrorism and organised crime cases but also to protect "major interests in foreign policy" and "economic, industrial or scientific interests".
Suspects and their associates can be spied on and located through their mobile phone and digital communications and their homes, cars and computers searched.
The law authorises the use of IMSI-catcher eavesdropping devices to record suspects' conversations, as well as those of people near them, in cafés, stations or courts.
The journalists argue that the law discourages whistleblowers or other sources from talking to reporters.
They can be identified through surveillance of reporters, who themselves may not even be aware they are being snooped on, the APJ argues.
Lawyer Patrice Spinosi argues that the case has wider implications for civil liberties.
"Anybody can be snooped on," he told Le Monde newspaper. "Via the press this is a criticism of the possibility to administratively listen in on people without any real control by the whole population."
"Fear of terrorism should not make us forget fundamental freedoms, in particular the right to inform," APJ president Pierre-Antoine Souchard told the paper.