Police detain topless Extinction Rebellion protesters in London

The transcript discusses a peaceful protest where participants support Extinction Rebellion and free speech. Despite not disrupting the public, the police impose restrictions, preventing the use of a PA system and confining the protest to a non-disruptive area. The protestors express frustration over the police's orders from higher authorities, emphasizing their non-violent approach and the importance of their cause.

Why does the speaker believe they should be allowed to use a PA system?

What does the speaker mean by 'orders from on high'?