All things are lawful, not all things are just.

Lots of bad things are done in the name of justice.
And sometimes I think folk forget this is a cleaning forum and not the US's First Amendment.
Also, the UK does not have freedom of speech. Say the wrong things in this country and you'll get locked up. If you threaten, cause alarm, abuse, harass, distress, cause a breach of the peace or be overtly racist, you will be breaking the law.
With great freedoms comes great responsibility. Window cleaners aren't ready for that yet, so it seems.