he agreement is aimed at improving the enforcement of intellectual property rights by setting international standards for dealing with copyright infringements.
The Polish protests coincided with calls by advocacy group La Quadrature du Net for opposition to ACTA in the same way that stalled controversial Stop Online Piracy Act (SOPA) and Protect IP Act (PIPA) in the US.
Critics of the proposed US and EU legislation say it could lead to censorship of the internet.
Despite the attacks on the websites of the Polish prime minister, parliament and other government offices, the Polish government said it will sign the treaty on Thursday.
Opponents of ACTA in Poland say the government has not carried out sufficient public consultation on the issue. But Polish officials say ACTA does not change Polish law or the rights of internet users and internet usage, according to the BBC.
A message from Twitter user @AnonymousWiki after the sites went down said: "Dear Polish government, we will continue to disrupt and interfere with your government official websites until the 26th. Do not pass ACTA."
The user later posted: "We have dox files and leaked documentations on many Poland officials, if ACTA is passed, we will release these documents."
The agreement has so far been signed by the US, Australia, Canada, Japan, Morocco, New Zealand, Singapore and South Korea.
The EU Parliament’s development committee’s first debate on its draft opinion report on ACTA is set to take place this week.
“This disastrous draft opinion report is deceptive and tries to justify extremist repressive measures to protect the outdated regime of copyright, patents and trademarks,” La Quadrature du Net said.
This story was first published by Computer Weekly