Saudi Arabia's King Abdullah has ratified a new counter-terrorism law that rights activists say criminalizes speech critical of the government or society.

The law states that any act that "undermines" the state or society, including calls for regime change in Saudi Arabia, can be tried as an act of terrorism. It says that any Saudis and non-Saudis, both in the kingdom and abroad, can be tried under the new law for assisting in such acts.

Police can also raid homes and offices without prior approval. One activist says the law essentially codifies practices already largely in place in Saudi Arabia. He spoke anonymously for fear of retribution.

The law, which is 41 articles long, went into effect Sunday. It was published in full in the government's official gazette Um Al-Qura Friday.