More than 50 people were taken to hospital after the police raid
Campaigners have expressed dismay that a policeman acquitted of brutality last month will be in charge of security at next year's G8 summit in Italy.
Franco Gratteri was one of those in charge during the 2001 G8 meeting in Genoa, which was marred by violence.
While he was cleared of related charges, colleagues were convicted.
Mark Covell, who was beaten unconscious by police at Genoa, said he feared police had not learned lessons and violence would flare again next year.
Genoa 2001 became notorious for violent street clashes between anti-globalisation protesters and police, that left many people injured on both sides.
Thirteen police officers were convicted last month in connection with attacks on defenceless demonstrators at the Diaz School in Genoa in 2001. But Mr Gratteri and several other senior commanders were cleared of responsibility by the judge.
At a press conference in London on Friday British Foreign Secretary David Miliband was accused of hypocrisy and inaction by a lawyer representing two of the five British Diaz victims, Richard Moth and Nicola Doherty.
Mr Miliband celebrated the 60th anniversary of the universal declaration of human rights this week, said lawyer Matt Foot, but had done nothing to press for compensation for those injured by the police seven years ago.
At a separate trial earlier this year another 13 police officers and doctors were convicted in connection with ill treatment of protesters at the Bolzaneto detention centre in Genoa.
Norman Blair, another British demonstrator who was injured in the Diaz raid and then detained at Bolzaneto, said: "I am deeply disappointed by the verdicts in these two trials. The people who ordered these raids have got off. It had to have been ordered at a senior level... these were not rogue officers."
The 26 police officers convicted in the two trials may not serve a single day in prison due to a law on the statute of limitations, introduced by Prime Minister Silvio Berlusconi.
Benny Coelle, a German demonstrator who suffered a broken jaw and fractured cheekbone at Diaz, said it was ironic that while the police officers convicted were given light sentences 25 people convicted of rioting had been given heavy jail terms.
Next year's G8 summit will take place on the island of La Maddalena, off the coast of Sardinia.
But Mr Covell said: "The most important thing is that Genoa never happens again. The Italian chief of police [Dr Antonio] Manganelli says it won't happen again despite appointing Gratteri to be head of security at La Maddalena."
He said he feared violent clashes between the police and demonstrators, especially angry Italian youths who had been disillusioned by the legal system.
Carlo Baroschmitt, a representative of the Genoa Legal Forum, said: "Not only have none of the 26 officers convicted at the Diaz and Bolzaneto trials spent a day in prison but some of them have been promoted."
And he added: "Some of the top police people at Diaz will be in charge at La Maddalena. In recent years one of them has become the head of the Italian anti-terrorist police and one of them has become the head of the Italian secret service."