Yes it was done by the Taliban in Afghanistan - I see this as one of the most reprehensible acts in modern history. While it was a religious shrine and not a burial mound as are the pyramids, it had great historical and cultural value. Its loss is incalculable and reveals that those fanatics are beyond all manner of negotiation, tact, and diplomacy.
Compare this with the Shiia Imani government of Iran - under Ayatollah Khomeini, it was decided that Iran will honor its Sumerian past. and would preserve all monuments including the Ziggurat burial mounds and shrines:
I checked with the Muslim Brotherhood website to see if it had any details on this story about destroying pyramids but could not find any:
Ikhwanweb :: The Muslim Brotherhood Official English Website
Mind you, the Muslim Brotherhood is considered moderate among Jihadists and al-Qaeda views them as enemies because they chose to participate in democratic elections. It recently suffered a major defeat in Libya's elections:
Muslim Brotherhood fell 'below expectations' in Libyan elections | World news | guardian.co.uk
Last month, Morsi met with Coptic leaders and was well received:
Morsi Meets With Coptic Leaders, Fails to Soothe Tense Christians - Al-Monitor: the Pulse of the Middle East
"
Despite the fact that Copts raised crosses and participated in Morsi’s victory celebrations, there were some clear indications that the community at large felt concerned. Their concern reached a point that drove Morsi himself to meet with Coptic church representatives in the last few days. In the meetings, he tried to reassure them that he considered Muslims and Copts to be equal citizens in rights and responsibilities.
Morsi’s message received a positive reception from Coptic Church officials. The Church's youth bishop, Bishop Moussa, stated: “We were pleased to have met the president, whose heart is filled with love, kindness and modesty. His overwhelmingly kind thoughts for all Egyptians, including the Copts, eased our minds.”
If Morsi is to maintain a good relationship with 6 million Coptics, then all talk of destroying their old burial relics better get refuted and soon.
