Guardian: News that police have stopped a plan to set off explosives during the G20 summit this week is going to make everyone concerned even more twitchy — and frankly I wouldn’t have thought that was possible. Police have been warning for weeks that serious disruption is planned. Protesters have been warning for weeks that police are coming down too heavily. Some protesters are trying to disown other protesters. Nerves are fraying everywhere you look in the countdown to the demonstrations planned …