Yeah, I'd say that's verboten. Whether you're trying to influence another player (the understood message being "be nice, and maybe you'll get more free stuff!"), or are facing elimination and just want to spite your conqueror.
And if it's the later case, seeing as how this is an anonymous, every man/woman/child for him/herself game, what would be the point, except mere vindictiveness (which in a regular MP game, I'd totally be for
)?