EU Justice Commissioner Viviane Reding told the European Parliament Web sites need to give people greater control over their data, NewScientist.com reported Thursday.
"I want to explicitly clarify that people shall have the right -- and not only the 'possibility' -- to withdraw their consent to data processing," Reding said.
Reding said sites like Facebook must comply with EU laws, and urged greater powers for national privacy watchdogs.
"A U.S.-based social network company that has millions of active users in Europe needs to comply with EU rules," she said.
However, experts said the nature of the Internet will make a legal right to be forgotten unenforceable in practice. Once something is put online it can easily be copied and widely distributed, and deleting the original will do nothing to stop people from finding a copy elsewhere.
Experts say the only real way to ensure fool-proof privacy protection is not placing data online in the first place.