Internet users in Iran are reporting error messages when trying to access major websites from inside the country Friday.

Gmail, Google Reader and Facebook are just some of the blocked sites, according to The Washington Post.

Some Iranians are guessing their connectivity woes are being caused by the Iranian government. The country celebrates the 33rd anniversary of the Islamic Revolution from mid-February until March every year. The government may be restricting Internet access during this politically charged event to prevent anti-government demonstrations from forming online.

All the websites being plagued by error messages use HTTPS, a more secure version of the HTTP protocol that helps keep Internet users' information private.

Other encrypted sites are also being blocked, including that of proxy servers, which some Iranians use to circumvent government blocks of Western websites, according to The Verge. Some are fearing this mass block is the first stage of Iran's "national Internet," a government plan to isolate digitally savvy Iranians from the rest of the Internet.

The Internet has played a vital role in Iranian political rallies in the recent past. Mass protests after a disputed election in 2009 were dubbed the "Twitter revolution" because protesters used the social network to organize themselves. The Internet slowed to a crawl during 2010's anniversary of the Islamic Revolution. And Iranian protesters used the Internet again last year to coordinate solidarity marches with Arab Spring demonstrations in the Middle East.

Do you think governments should shut off encrypted websites before potentially explosive events? Sound off in the comments below.