Syrian security officers were deployed outside parliament Friday to guard against possible anti-government demonstrations, but by early afternoon, no protesters had gathered.
Campaigns on Facebook had called for a day of "anger" in the Syrian capital, Damascus, on Friday and Saturday.
One page, titled "The Syrian Revolution 2011," has drawn nearly 15,000 virtual fans. The group, which according to news reports was set up by Syrians living abroad, is also calling for peaceful demonstrations at Syrian embassies in several countries, including the United States, Britain, Canada, Denmark and Sweden.
The activists are demanding reforms in Syria, including the transition to a pluralistic democracy.
The use of social media sites to organize anti-government demonstrations reflects recent events in Tunisia and Egypt.
However, one activist told pan-Arab broadcaster Al Jazeera that Syrians are "very scared" of the state and the intelligence service.
Human Rights Watch accused Syria's government this week of intimidating and harassing demonstrators expressing solidarity with Egyptian protesters.
The New York-based rights group said it learned from an organizer of a solidarity vigil Wednesday in Damascus that a group of 20 people dressed in civilian clothing beat and dispersed the 15 demonstrators at the gathering. Human Rights Watch said nearby police did not intervene.
The group's Middle East and North Africa director, Sarah Leah Whitson, said it appears President Assad's security forces are "no longer content" with simply banning protests, and said they seem to be encouraging thugs to attack peaceful demonstrators.
Some information for this report was provided by AP and AFP.