This morning we woke up to the horrible news that Alexander Kuznetsov and his daughter were arrested after protests in Moscow. A petition has been started, let me simply quote the message that Richard Thomas sent on the EAGER and COW mailing lists:
The algebraic geometer Alexander Kuznetsov -- winner of the European Mathematical Society prize of 2008 -- has been arrested for peacefully protesting the detention of Alexey Navalny.
A petition asking for his release is here Free Alexander Kuznetsov. The more people sign, the more impact it will have in the Russian press.
Update, taken from the petition website:
Sasha's trial has been postponed until Wednesday; he has been released until then. His daughter has been released with a fine. Please continue to sign to express solidarity with all the mathematics students and members of the public who are also detained.