So they talk to Met liaison - in the meantime coppers are shipped in from all over the country to police the occasion.
Were they told about the arrangements? Doubt it.
The foot soldiers rarely get told the detail.
Can you use a luggage strap to "lock on"? I have no idea but it seems the professional protesters can use many things to do such from superglue to concrete.
Me? I would just pull really hard until something gives way.... like the French police do.
Nothing "sinister" about suspicion is there?