'Too few trained police' for G20
The committee also called for kettling to be used sparingly.
"The police must have reasonable grounds to believe that the protesters being contained are liable to cause disturbances elsewhere and innocent bystanders and non-violent protesters must be allowed to filter out," it said.
"It is not acceptable for a blanket ban on movement to be imposed.
"The police must be aware that their behaviour will be monitored, recorded and instantly made public via the internet. They must modify their behaviour and briefings accordingly."
Chairman of the committee Keith Vaz said the public "clearly don't understand" the reasons for using kettling and other public order strategies.
"What's acceptable, what's within the police rule book - the use of distraction tactics, for example, slapping or hitting people - shocked the public," he told the BBC.
"Therefore, they need to look again at these tactics and consult the public to decide whether or not such tactics can be used again."
http://news.bbc.co.uk/1/hi/uk_politics/8121608.stm