Yea! He may start droneing people in Pakistan..... that be horrible.. aa wait .. the US is already doing that.
And it's not just Putin who has this problem: pretty much every country that is not Saudi Arabia and depends on oil prices > 40$ a barrel (Russia e.g. needs 100$ a barrel to maintain financial stability!) will have or already has problems.
The only upside of this situation is that the low oil prices are actively fucking up ISIS. No pay, no fighters.
But they also tax their populace, so if they increase taxes unreasonably, perhaps people will revolt against them. The consequences for the innocent are horrible though.