A number of media outlets have begun reporting that the anti-Morsi protests in Egypt are "the largest protests in human history" (or some variation thereof). Most of these outlets have been right-leaning: The Examiner, the Heritage Foundation, and Breitbart.com have all perpetuated the claim, which has also caught fire on Twitter.
But is it true? Probably not. All of these outlets cite this single tweet as their source:
BBC:"The number of people protesting today is the largest number in a political event in the history of mankind. Keep impressing .. Egypt. "-- Naguib Sawiris (@NaguibSawiris) June 30, 2013
Nabuib Sawiris is a wildly wealthy businessman who chaired Orascom Telecom Holding when it lucratively launched North Korea's first cell phone operator. In recent years, Sawiris has dipped his toes into politics, founding the Al Masreyeen Al Ahrar party, which opposes Morsi. In 2011, Sawiris, a Coptic Christian, was accused of racism and Islamophoboa after tweeting an offensive cartoon. He is a vocal supporter of the anti-Morsi protests.
Sawiris' tweet cites the BBC, but when I asked the outlet's publicist, he doubted whether the organization had put forth such a statement.
"I can't find any BBC source for this and I'm not aware of one," he said, although given their "vast amount of output," he couldn't say for certain.
Whether or not BBC made the claim, it is almost certainly untrue. A number of previous demonstrations, including the February 15, 2003 anti-war protests, have probably drawn more people.