29 March,2013 01:34 AM IST | | Agencies
Hundreds of thousands of Internet users unsuspectingly took part in one ofthe Internet's biggest-ever cyber-attacks after their broadband routers were subverted.
Millions are believed to have been hit when the spam-fighting group Spamhaus was targeted by a web filtering firm it had blacklisted.
The revenge attack, carried out by overloading servers, was so large it has hit popular services such as Netflix - and experts fear it could escalate to affect online banking and email services.
One effect of the attack is that Internet users accustomed to high-speed connections may have seen those slow down, said James Blessing, a member of the UK Internet Service Providers' Association (ISPA) council.
"It varies depending on where you are and what site you're trying to get to," he said. "Those who are used to it being really quick will notice."
Five national cyber police forces are said to be probing the attacks.
Spamhaus, based in London and Geneva, is a non-profit organisation that aims to help e-mail providers filter out spam.
The company recently blacklisted Dutch firm CyberBunker, which is housed in a former Nato bunker offering services to any website "except child porn and anything related to terrorism".
US expert Patrick Gilmore said: "These guys [CyberBunker] are mad. They got caught. They think they should be allowed to spam."