Is it legal for a random person (not law/parking enforcement) to pick up the wiper and but whatever garbage they want under there?
Can I put my used McDonald's bag under someones wiper?
This is an all-purpose section that, for example, makes it possible to arrest someone who is walking down the street trying the handles on car doors to see if they are unlocked - even if they don't find any that are unlocked. I guess it would probably apply if someone broke off a windshield wiper while putting a pamphlet there. If someone was sufficiently irate, it might even apply to a used McDonald's bag being put under someone's wiper.
Interpreting "Legal speak" is not like a compiler checking syntax. It's more like interpreting a project's specifications in a way that makes sense. Just as in any important job, judgement matters.