[ozim]

That's not gonna happen.

I can put your e-mail in and type out all kind of swear words or put in phishing link in contact for of a company and you would never know it came from me and you would blame that company.

I had spammers trying that all the time, multiple times they had some confirmation for buyer of their services - well only me got that info because from any public form we always sent out confirmation and "was it you? if not disregard, please" where content went to our special place so it would be safe, like our sales person not clicking some bs link from such contact form.

[ycombinator_acc]

It does happen and is very handy.

Your far-fetched example is easily circumvented with a disclaimer saying this is a form copy (duh). I've never received one that didn't say that.

[ozim]

For authenticated form no problem. For unauthenticated form it is not far-fetched.