Curiously, the US State Dept. 2012 Report on International Religious Freedom, decried the fact that “a government policy since 1967, repeatedly upheld by the Supreme Court and routinely enforced by the police, who cite security concerns, denies non-Muslim worship and prayer at the Temple Mount/Haram al-Sharif.”
The report says “only Muslims are allowed to pray at the site, although their access is occasionally restricted due to security concerns. The Israel National Police regulates traffic in and out of the compound and removes non-Muslim visitors if they appear to be praying.”
Also, according to the US government report, “The Waqf (Jordanian agency controlling the compound) does not allow non-Muslim religious symbols to be worn on the Temple Mount/Haram al-Sharif.”
It’s not a secret, then. It just doesn’t upset anyone.