Leaders are calling on Turkish President Abdullah Gul to veto the bill, which passed the nation's parliament Thursday.
The legislation gives the government the authority to block any website without a court order and would force Internet providers to maintain data on users for as long as two years, and provide it to the government on request, the Hurriyet Daily News reported.
"The president should take up a position on behalf of democracy and freedom. The impartiality of the president means something different," opposition leader Kemal Kilicdaroglu told reporters in Istanbul Friday. "To say that 'regulations against laws come and I sign them despite clearly [problems with them]' degrades the office of the president. The president pledges loyalty to the Constitution. And he has to do what is necessary. A president cannot defend bans. A president cannot defend legal regulations which were brought by a government saying they will limit freedom."
The U.S. State Department said the ban does not fall in line with international norms on free speech.
"We share the concerns recently expressed ... that these proposed measures are not compatible with international standards on freedom of expression," State Department spokeswoman Jen Psaki said.