Hackers have attacked several Indonesian government websites today to protest against the arrest of a man who defaced President Susilo Bambang Yudhoyono's official Internet homepage.

The police arrested Wildan Ashari, 20, last Friday for replacing the homepage of Susilo's website, www.presidensby.info earlier this month with the message: " Hacked by Jemberhacker team ".

Wildan, an employee at an Internet cafe in the Jember district of the East Java province, could face up to 12 years in prison if found guilty, the police said.

Fellow hackers then launched "Operation Free Wildan" and attacked several government websites yesterday and today, including those of the Justice Ministry and the Central Bureau of Statistics.

"Government of Indonesia, you cannot arrest an idea. No army can stop us," hacker group Anonymous Indonesia said in a post on Twitter .

The defaced pages appeared to have been removed later in the day.

Police said Wildan did not appear to have a political motive, but refused to release him yet.

"Apparently he had too much time on his hands," said Arief Sulistyo, director of the police special economic crime unit.

However, Information Technology Minister Tifatul Sembiring said that Wildan was unlikely to be given a harsh punishment.

"We have caught many hackers, but they were only reprimanded and advised to use their skills for positive things," he added.

- dpa