I REALLY REALLY want someone to do this with a huge amount of google image thumbnails so that the google crawlers just start hitting google servers. Would it be considered malicious to do such a thing?
Maliciousness is usually described in the context of intent. So your first sentence should provide the answer to your own question. Is there a way to do what you describe such that the result is gratifying and yet doesn't cause significant duress on Google's servers and employees?