According to Interpol police in Latin America and Europe have arrested 25 suspected members of the Anonymous hacking group.
The authorities in Argentina, Chile, Colombia and Spain carried out the arrests and seized 250 items of IT equipment and mobile phones.
Those arrested are aged between 17 and 40.
The operation follows cyber attacks on Colombian and Chilean websites including those of the Colombian Ministry of Defence and the presidency.
Anonymous is a loose international network of online activists which describes itself as an "internet gathering".