From BBC News:
An activist group that temporarily blocked access to key Australian government websites plans to continue its cyber attacks, the BBC has learned.
The group, known as Anonymous, was protesting against the Australian government’s proposals to apply filters to the internet in the country.
A man claiming to be a representative of the group said that around 500 people were involved in the attack.
The method they are using is known as Distributed Denial of Service (DDoS).
DDoS is illegal in many countries including the United Kingdom. There is no indication that the attack was carried out from within Britain. DDoS attacks typically call on machines in many different nations, making them hard to trace.
The sites were intermittently blocked on 10 and 11 February. The action has been condemned by various bodies including the Systems Administrators Guild of Australia (SAGE-AU) and Electronic Frontiers Australia.