In the letter, the group asks the European Commission's assistance in evaluating the impact of the US government's online spying program PRISM on privacy of European citizens.
"We need guarantees that that data will not be used to analyze activities of citizens of other countries," Kunčinas told BNS.
In his words, potential use of the collected data would pose a threat.
"The collected data, of course, poses a certain threat, if it is purposefully used against somebody. That's a really existing threat. They are free to do whatever they want with their citizens, that's the matter of that country. But when they collect personal data of citizens of other countries, we need them at least to not to use them for the surveillance of those citizens," Kunčinas said.
Kunčinas is a member of the so-called Article 29 Data Protection Working Party. One of the purposes of the letter to Reding is to give to the European Commission an opinion on community laws affecting the right to protection of personal data.
In June, the United States confirmed the existence of secret online surveillance program PRISM after Edward Snowden, a former officer of the National Security Agency, revealed that the agency collected large amounts of data on users of Google, Facebook, Skype, and other American companies in Europe and other countries.
Washington was also accused of having spied on EU and German institutions and officials.