They ended the free election of governors.
They placed greater restrictions on the media.
They curtailed online freedom.
And they expanded the definition of extremism to the point where it meant anything the Kremlin doesn't like.
Vladimir Putin's regime did all these things in response to terrorist acts and in the name of preventing future terrorism.
But in fact, these things did little if anything to achieve that goal.
From the 2002 Nord Ost theater siege in Moscow to the 2004 Beslan school massacre to the 2013 bus and train station bombings in Volgograd, the Kremlin has treated terrorist acts as opportunities to consolidate power and stifle dissent.
As a result, power has been consolidated, dissent has been suppressed -- and terrorism has continued.
And just days after this week's tragic bombing in the St. Petersburg Metro, Putin's Kremlin is at it again.
Yury Shvytkin, the deputy chair of the State Duma's Defense Committee, has proposed a moratorium on public demonstrations in response to the attack.
And State Duma Deputy Vitaly Milonov is introducing legislation banning online calls for unsanctioned demonstrations and requiring all social-network users to register with their passport details.
And this, no doubt, is just the beginning.
Because for Putin's Kremlin, terrorism isn't just a tragedy and a crime -- it's also an opportunity.