I don't recall that David Suzuki ever cost Canadians significant amounts of money in policing. That's what OP was talking about - the cost of policing. There is also the significant cleanup.

If David Suzuki conducted a protest, then his organization would be expected to pay for the license, the cleanup, and the policing.

I don't know what the final bill will be, but this one event is well into the tens of millions. Nobody from the protest seems too interested in paying for these expenses, and instead are hoping to leave it to Canadians to pay through taxes.