The Saudi grand mufti on Friday called social-networking website Twitter full of lies, a day after the site announced that it would begin restricting Tweets in specific countries.

The news from the social media platform is renewing questions over how it will handle issues of free speech as it rapidly expands its global user base.

Until now, Twitter had to remove a tweet from its global network if it received a takedown request from a government.

But the company said in a blog post published on Thursday that it now has the ability to selectively block a Tweet from appearing to users in one country.

“Starting today, we give ourselves the ability to reactively withhold content from users in a specific country while keeping it available in the rest of the world,” the Twitter blog said.

Twitter gave as examples of restrictions it might cooperate with, such as pro-Nazi content in France and Germany, where it is banned. It said that even with the possibility of such restrictions, Twitter would not be able to operate with some countries.

“Some differ so much from our ideas that we will not be able to exist there,” it said.

“As we continue to grow internationally, we will enter countries that have different ideas about the contours of freedom of expression.”

In the interest of transparency, Twitter said, it has built a mechanism to inform users in the event that a tweet is being blocked. A Twitter spokeswoman declined to elaborate on the blog post.

Saudi Grand Mufti Abdul Aziz al-Sheikh said in his Friday sermon in Riyadh that Muslims should avoid being a “source or feeding” Twitter, the London-based Al-Hayat newspaper reported.

Twitter was a place “in which people are invited to throw charges between them, and to lie in a manner that brings fame to some,” he said.

The 71-year-old cleric called on those present to warn people about such sites, adding that positive sites do exist on the Internet concerning science, business and God.

Despite the grand mufti’s caution over the website, Saudi billionaire Prince Alwaleed bin Talal’s Kingdom Holding Company announced in December that it would invest $300 million in the social-media site.

“Our investment in Twitter reaffirms our ability in identifying suitable opportunities to invest in promising, high-growth businesses with a global impact,” Alwaleed said, according to BBC.

According to the San Francisco Chronicle, critics question whether the site has succumbed to pressure from certain governments or even its new Saudi investors, with some activists tweeting for a one-day Twitter boycott against the company.

Twitter’s acknowledgment that it will censor content represents a significant departure from its tone just one year ago, when anti-government protesters in Tunisia, Egypt and other Arab countries coordinated mass demonstrations on the social network and, in the process, thrust Twitter’s disruptive potential into the global spotlight.

The platform is still used for ongoing conflicts in Syria, where foreign journalists are mostly denied access, and in Saudi Arabia’s Eastern Province, where Shi’ite activists have staged rallies in recent months.

As the revolutions brewed last January, Twitter signaled that it would take a hands-off approach to censoring content, in a blog post titled “The Tweets Must Flow.”

“We do not remove tweets on the basis of their content,” the blog post read. “Our position on freedom of expression carries with it a mandate to protect our users’ right to speak freely and preserve their ability to contest having their private information revealed.”

And last year, Twitter general counsel Alex Macgillivray declared that the company was “from the free speech wing of the free speech party.”

Still, some open Internet advocates said it appeared Twitter did the best it could to navigate the dueling responsibilities of complying with local law and upholding free speech.

Twitter would be banned outright in many countries if it did not agree to restrict tweets, said Cynthia Wong of the Center for Technology & Democracy.

“The question is: What’s best for freedom of speech?” Wong said.

“If Twitter was completely blocked from certain countries, is that really better? It looks like Twitter has done a good job in thinking through how to mitigate the human rights harm in complying with local law.”

Twitter’s move highlighted the frequent tensions over freedom of speech and privacy issues between foreign governments and Internet companies such as Google and Facebook as they expand rapidly overseas.

In 2010, Google relocated its Web search engine to Hong Kong, following a very public spat with the Chinese government over its refusal to bow to Beijing’s Web censorship requirements and a hacking episode that Google said it had traced to China.