By Brian Wheeler
Political reporter, BBC News, at the Labour conference in Manchester
I think it was the moment a colleague was threatened with being locked in the toilets that it hit home.
Police have been taking few chances in Manchester
We are used to security at Labour conferences being tight and this year has been no different.
The stewards have been friendlier. No elderly peace campaigners have been manhandled from the hall.
Indeed Walter Wolfgang, still going strong at 83, has been able to wander the cavernous exhibition halls at Manchester's G-Mex centre unmolested.
There were even some fairly rowdy scenes on the conference floor on Wednesday as delegates protested at Unison leader Dave Prentis's speech being cut short during the health debate.
But the double header of Tony Blair's farewell speech and a visit by Bill Clinton meant security in and around the centre on Tuesday and Wednesday was as tight as I have seen it.
My colleague made the mistake of visiting the loo just as Mr Clinton and his entourage were about to sweep through his part of the building.
"We are clearing the area," yelled a security guard.
"If you don't leave the toilets now you'll be locked in."
The security bill for Labour's conference this year is reportedly £4.2m with 1,000 police, from the local Greater Manchester force and the Metropolitan Police, on duty every day.
Around 1,250 officers were also on duty at last Saturday's anti-war demo in the city centre which passed off peacefully.
The streets around the G-Mex centre have road blocks and the area is closed to traffic. A no-fly zone is also in operation over the city centre. You occasionally spot a sniper on a roof top.
Everyone who enters the security cordon - or "island" as the police refer to the fenced in area around the G-Mex, the Midland and Radisson hotels - has to pass through airport-style scanners, watched by machine-gun toting officers.
The seemingly unarmed officers on duty in the streets around the conference centre seem to spend most of their time offering directions to bewildered delegates more used to navigating the seafront at Blackpool or Brighton.
They were also telling delegates to remove their conference ID badges from their necks as they wander about the city centre after dark.
"Don't make yourself a target," one officer advised, adding "we want you to enjoy your stay in Manchester".
The nearest we have come to an incident was in St Peter's Square on Wednesday afternoon, a few hundred metres or so from the "island", when a small number of anti-war protesters were suddenly surrounded by dozens of police officers, including mounted police, dog handlers and video surveillance unit.
'Over the top'
The protesters - from a local group called Stop the Warmongers - wanted to release some balloons containing anti-war messages.
But they were hemmed in all sideds by police officers, who must have outnumbered them by about three-to-one.
As one passer-by commented "it looked more like a police demonstration".
There were no arrests and the 40 or so demonstrators were eventually dispersed peacefully, by being allowed through the police line in pairs.
But there was considerable anger among the protesters who felt the police reaction had been heavy-handed.
Rosalynd Arnold, who lives in Manchester, said: "It was completely over the top, completely stopping free speech and stopping the people of Manchester from knowing what is going on in there."
But as Tony Blair and Home Secretary John Reid toured the specially-built police control room on Thursday morning to thank officers for their efforts the main feeling will, no doubt, have been a sense of relief that a serious incident had been avoided.