Slide joins Web services such as YouTube, Facebook, and MySpace that have been barred by countries including Turkey,
Turkish law forbids insults to "Turkishness," state institutions or insults to Mustafa Kemal Ataturk, the founder of modern Turkey in the 1920s and 1930s. Famous authors, academics, and political figures have faced prosecution.
John Duncan, Slide's general counsel, said the company started getting complaints in February from Turkish users of Slide services shortly after a court ordered Turkish Telecom, the nation's Internet service provider, to block Slide Web sites.
The order appeared to have been handed down on January 24 by a court in Civril, Turkey, Duncan said. Civril is located about 185 miles southwest of the capital of Ankara.
Slide officials said they never received formal notice of the action against the company. The company said it had been unable to identify the offending material but that Turkish Telecom had complied with the court's order.
Duncan said Slide's policy was to comply to remove offensive content from its site.
"It is not exactly clear to me what the substance of this material was.
While initially only the Slide.com home page was affected, in recent weeks the blockage has grown to cover most applications on Slide's site and inside Facebook, where Slide is the most popular independent provider of applications.
A translation of the Turkish language court order obtained by the company accuses Slide of "harboring pictures and articles that are considered to be insulting to Ataturk," the San Francisco-based company said on its blog.
Seeking a work-around for users
Slide said it has hired local representatives in Turkey who have contacted the national government to try to resolve the issue. Meanwhile, the company said it is working on alternative ways for Turkish users to reach its site.
The San Francisco-based privately owned company offers a popular online program to create picture slide shows aimed at users of social networks such as Facebook and MySpace.
Slide had around 150 million users worldwide in January, according to market research firm comScore. This tally does not include Facebook users.
Its "Top Friends" list is the most popular application on Facebook, where it has more than a 1.8 million active users.
The Facebook social network phenomenon has caught fire in the past year in Turkey, which is the No. 4 ranked country in terms of active Facebook users behind the United States, Britain, and Canada.
As of February, Facebook counted around 2.85 million users in Turkey. Slide estimates that around 50 percent of Facebook users worldwide use its services and that the ban in Turkey affects hundreds of thousands of the country's Web users.