Turkish police have arrested 32 people believed to be members of hacker collective Anonymous.
The group has been active in Turkey protesting against government plans to set up a national net filtering system.
Action against the group was started following a complaint from the Turkish directorate of telecommunications whose website was hit by Anonymous.
The arrests follow similar action by police in Spain who detained three members of the hacker group.
On 22 August, Turkey is planning to turn on a system that demands people sign up for one of four filtering packages designed for different types of users.
The Turkish government claims this system is needed to protect younger web users from net-borne dangers. Critics, including Anonymous, say the filtering system will be used to monitor web activity and suppress dissent.
Many Turkish people have mounted street demonstrations to protest against the introduction of the filters.
On 10 June, Anonymous took action in support of these protests by knocking several Turkish government websites offline. It used an attack tool known as the Low Orbit Ion Cannon (Loic) which bombards targets with so much data that they become overwhelmed.
The arrests came only days after the attacks were mounted and Turkish police may have exploited failings with Loic that allow users of it to be traced. Arrests were made in 12 cities around Turkey and eight of those detained are believed to be minors.
On 10 June, the Spanish national police announced that it had arrested three people believed to be members of Anonymous. In retaliation, Anonymous took the national police service site offline for a few hours.