From the BBC
"The Metropolitan Police confirmed several arrests were made at demonstrations in the capital.
The force said "lock-on devices" - which protesters can use to secure themselves to things like railings - had been seized.
But Republic said officers had "misconstrued" straps meant to secure their signs in place."
Police use their common sense all the time. It's not turning a blind eye or corruption. It's using their common sense to deescalate situations.