This is called an "abundance of caution," and is perfectly understandable to anyone that hasn't been living under a rock for the last twenty years.
In 'abundance of caution' the police should tear open the trunk of any vehicle parked anywhere with a sealed trunk of any vehicle left unattended, since you can never be too sure there's not a pressure cooker in there, or god forbid.... some bags of fertilizer.
Were you paying attention to what two idiots did with pressure cookers in Boston a few years ago?
So if the idiots had put their stupid s*** in a laptop bag or suitcase, then you would say the cops should break into any car left unattended with a suitcase or laptop bag visible and detonate the bag?
Idiots do a lot of stupid things all the time with ordinary things.
That doesn't make mere ownership and display of one of the things some idiot or another has done some stupid thing with in the past a crime or probable cause for police invasion and excessive force in the unnecessary destruction of personal property.
There's not a current legitimate emergency situation that justifies the mass seizure or destruction of innocent people's pressure cookers.