We have a form on our public website that users can use to request an account from us. Just today we had hundreds of form submissions that said "crawler typing text..." in the email and name field, and a random string of numbers in the password field. The password did not vary between submissions, and this didn't seem to be a DOS attack on the domain; so I'm guessing this was just a normal web crawler that was malfunctioning.
Is this a situation where we need to add a no-crawl header to the form page? I haven't ever heard of crawlers intentionally submitting forms, but I haven't done much SEO stuff.