have much stronger stipulations on purchasing pressure cookers

In light of the recent tragedy at the Boston Marathon, I am appalled at how easily a person can purchase the device used as the vessel to carry the bomb that exploded. Anyone can walk into a store that carries pressure cookers, and buy one. There are no current background checks, no waiting period, and no way to track the pressure cooker once it has been purchased!
I feel that with the much deeper look we are taking into gun control after the recent tragedies that have claimed lives in schools as well as other places, and since we are blaming these horrific events largely on the weapons used, logic would dictate that the same rules should apply here.
Also, if water was used as the "explosive" in this bomb, it should be regulated as well as a potential dangerous material.