Story highlights

The bill would fight counterfeiting and piracy

Opponents say it amounts to Internet censorship

Poland signed the treaty Thursday

CNN  — 

Thousands of protesters have taken to the streets of Poland over the signing of an international treaty to enforce intellectual property rights on the Internet.

Police said more than 10,000 people have taken part in the countrywide protests, which began Wednesday and are set to continue Friday. A group of lawmakers in parliament also protested the signing Thursday in Tokyo by the Polish ambassador to Japan.

The legislation must be ratified by the Polish parliament before coming into effect.

Protesters held signs and banners reading “No to ACTA.” Their protests were largely peaceful, though there were a few skirmishes in the city of Poznan, where protesters threw bottles at police.

Activists hacked several websites, including that of the prime minister, to protest the signing.

The activists say the treaty – called ACTA, or the Anti-Counterfeiting Trade Agreement – amounts to Internet censorship.

The European Commission describes ACTA as a “major initiative” designed to fight piracy and the counterfeiting of goods at the international level. It says the agreement would not censor or shut down websites and, unlike the SOPA bill recently put on hold in the U.S. Congress, it would not change legislation.

ACTA allows criminal procedures and penalties to be applied in cases of counterfeiting and piracy, such as the unauthorized copying of movies. Penalties would be applied to offenders as well as those guilty of “aiding and abetting” the crime.

The actual penalties would be up to the individual countries that have signed onto ACTA.

SOPA, introduced by the U.S. House of Representatives, and a sister bill in the Senate called PIPA, aim to crack down on copyright infringement by restricting access to websites that host or facilitate the trading of pirated content.

CNN’s Antonia Mortensen contributed to this report.