Yes, in the US water cannons bring up a lot of uncomfortable memories. It is also a big deal with fire departments, who after the abuses of civil rights protesters realized that they were on the wrong side of history by siding with the cops.
I work with a lot of fire fighters in a volunteer capacity, and one, a retired chief from Texas was telling me that in the 80's there was protesting in his town, and the cops wanted him to bring fire engines and hoses to blast people, and he refused. He was adamant that he wasn't going to allow another "Kent State" and remove people's trust in the fire department to protect them. The police threatened to use their authority to commandeer the trucks, so he personally took all the keys out of the engines and held them on his person so they would need to arrest him if they wanted to take them and use the water cannons on protesters. Very sensitive issue for fire departments now.