On 14 April 2007, an estimated 300,000 people marched in Ankara to protest against the possible candidacy of Erdoğan in the 2007 presidential election, afraid that if elected as President, he would alter the secular nature of the Turkish state.
On 14 April 2007, Kasparov led a pro-democracy demonstration in Moscow. Soon after the demonstration's start, however, over 9,000 police descended on the group and seized almost everyone. Kasparov, who was briefly arrested by the Moscow police, was warned by the prosecution office on the eve of the march that anyone participating risked being detained. He was held for some 10 hours and then fined and released.