Throwing tomatoes at a poster of a politician

Question

As a form of protest, imagine:

1. Printing a poster of a politician's face
2. Placing it on a wall (with permission of the wall's owner) in a generally public space
3. Handing out tomatoes to be thrown at the poster.

What legal troubles can arise?

EDIT: The jurisdiction is Canada, particularly Ontario. My apologies for not thinking of this detail.

Answer 1

If you contain and clean up the mess and don’t create a public nuisance, you’re good to go.