Spam to de-promote products?

[tashirosgt]

Are there cases where spam has been sent advertising a product by someone whose real purpose was to create animosity toward the product? (The situation that brings this to mind is on car forum, where I've been getting private messages advertising a software product ( something like a captcha system) whose purpose to keep spammers off of forums!)

[DBelton]

I'm sure it has happened before, but I don't know of specific cases right off hand.

In the world of commerce, they are cut-throats, and I'm sure that has already been thought of, and done.