ORGANISED protests and cyber attacks on council and police websites are "inevitable" in the run-up to Gwent hosting the NATO summit this September, according to the Chief Constable of Gwent Police.
Two-thirds of Britain's police support units are set to descend on Newport to beef up security around the summit, Jeff Farrar told Gwent's Police and Crime Panel on Friday, which he described as "the biggest security event the UK has ever hosted".
The security bill alone at previous summits has topped £60 million.
Chief Constable Farrar left the panel early in order to chair a meeting of "the gold group" which has 40 to 50 members discussing preparations for the event, which will be 10 times the size of the G8 talks with 140 VIPs needing security protection.
He said the force has visited the hosts of the last NATO summit, Chicago, and "bled them dry" of all relevant information.
Organisers will soon be appointing a briefing officer, who will tour local authorities and community councils giving updates on the latest intelligence concerning the summit.
"The UK hasn't hosted anything like it for 25 years," he said. "The Ryder Cup was like a children's sports day in comparison."
The secretary of state for Wales David Jones had previously described the forthcoming event as "the Ryder Cup on steroids".
The Chief Constable said the risks are "considerable" and said all four and five star hotels between Swindon and Swansea are booked up with delegates.
"Eight days before, we can expect protests," he said. "It is likely to have an impact but we have no intelligence to support that. It could be in Cardiff or London."
As part of the force's "gold strategy", along with protecting those attending and nearby residents, the reputation of Wales is paramount.
"We do not want it to be a Westminster event that appears at Celtic Manor and we get a legacy of [local] politicians not feeling that they had the right engagement," said Chief Constable Farrar. "I am determined that's not going to happen."
When he was in charge of the FA Cup final security, 12 to 15 police support units were needed with 25 officers each, he said.
The NATO summit will require more than 200 police support units, out of a total of 300 across the UK, of which Gwent only has three.
"At the moment all eyes are on the Commonwealth Games and people need to realise the significance of this [event]," he told councillors. "It has potential knock-on effects on the day-to-day performance of Gwent Police and that shouldn't be lost on us."
He said that intelligence coming in about planned protests had been "an eye-opener" as previous hosts had had bridges burned down.
"The Black Bloc are very organised especially around cyber attacks," he said of organised protestors. "Local authority website and police website attacks are inevitable. They are using social media to galvanise support."
A successful summit will be "a feather in the cap" of the force if all goes well, said the Chief Constable.
"There is nobody in the UK who's ever planned for an event like this, not even in the Metropolitan Police," he said.