Putin is putting through a bill to allow his government to persecute people who express anti-state sentiments.
http://news.yahoo.com/s/ap/20081217/ap_on_re_eu/eu_russia_treason_law
Just off the top of my head, I think Putin is afraid of unrest from his economy weakening. According to Gary Kasparov (the chess champion and source for all my news in Russia) Putin’s power is tied to oil and the economic success of Russia, so the potential collapse of the Russian economy is a looming threat to Putin’s base of power (money and prosperity). To counter the threat he is preemptively enacting a law that will allow him to jail citizens in the event the collapsing economy leads people to blame him for the down turn. The purpose of the law then is to protect and maintain a belief within the populous that Putin is not the cause of economic problems.