The Russian government this week blocked access to prominent websites that have been critical of President Vladimir Putin, amid heightened tensions in neighboring Ukraine. As Reuters reports, the Kremlin ordered national internet providers to block access to the blog of Alexei Navalny, a leading Putin critic, as well as a news site operated by fellow opposition figure Garry Kasparov, a Russian chess champion. The government also blocked access to two other independent news sites, Daily Journal and Grani.ru, under a controversial new law that went into effect on February 1st. The law allows Russian authorities to block any sites that call for unauthorized public demonstrations or publish extremist material.