Sissi's Egypt has banned 21 websites, including the main website of Qatar-based Al Jazeera television and prominent local independent news site Mada Masr, accusing them of supporting terrorism and spreading false news. Such a measure against free media is not unexpected with a neo-pharaoh who rules Egypt.
The blockade is notable in scope and for being the first publicly recognized by the government. It was heavily criticized by journalists and rights groups.
The state news agency announced it late on Wednesday. Individual websites had been inaccessible in the past but there was never any official admission.
Reuters found the websites named by local media and were inaccessible.
The move follows similar actions taken on Wednesday by Egypt's Gulf allies Saudi Arabia and the United Arab Emirates, which blocked Al Jazeera and other websites after a dispute with Qatar.
Qatar said hackers had posted fake remarks by its emir criticizing U.S. foreign policy but Saudi and UAE state-run media reported the comments anyway.
An official from Egypt's National Telecom Regulatory Authority would not confirm or deny the blockage, but said: "So what if it is true? It should not be a problem."
Two security sources told Reuters the 21 websites were blocked for being affiliated with the outlawed Muslim Brotherhood or for being funded by Qatar.
Cairo accuses Qatar of supporting the Brotherhood, which was ousted from power in Egypt in 2013 when the military removed elected Islamist President Mohamed Mursi following mass protests against him.
Ties between Qatar and Egypt were badly damaged after Mursi's fall. Doha welcomed a number of senior Brotherhood figures, although since then Qatar has asked several to leave.
Mada Masr, an Egyptian news website based in the country which describes itself as progressive and has no Islamist or Qatari affiliations, was also inaccessible.
Journalists at Mada Masr said the website was publishing articles on Facebook for now. It remains accessible outside Egypt or via proxy.
"Nothing explains this blockade more than a very clear intention from the authorities to crack down on critical media in ways that bypass the law," Mada Masr Editor in Chief Lina Attalah told Reuters on Thursday.
The website is registered in Egypt and its journalists are based in the country, she said. No one from the government contacted the management before or after the 21 websites went down.
CLIMATE OF FEAR
Two other local websites, including that of a print newspaper registered with the authorities, were also down, as were several Brotherhood-affiliated websites and Egypt-focused ones that publish from abroad.
The Huffington Post's Arabic website also was inaccessible, although the international version could be accessed.
State news agency MENA cited a senior security source as saying the websites were blocked because they supported terrorism and that the government would take legal action.
"A senior security source said 21 websites have been blocked inside Egypt for having content that supports terrorism and extremism as well as publishing lies," MENA said.
Mahmoud Kamel, who sits on the board of Egypt's official press union, said was a clear attack on freedom of speech.
"This move is unacceptable. We oppose all blocking of news websites but this is unfortunately part of the general climate of fear we are experiencing in Egypt," he told Reuters.
Egyptian authorities have cracked down on the Islamist, secular and liberal opposition alike since President Abdel Fattah al-Sisi, then the military chief, toppled Mursi.
Since then, hundreds have been killed and thousands arrested, including journalists. Sisi told CNN in 2015 that Egypt has "unprecedented freedom of expression".