[thelist] preventing (further) attempts to spam a site

[Sarah Adams]

One of my clients' sites has recently become the target of a spammer,
trying to submit spammy links via an info request form. I know how to
prevent them from doing this, but I'd like to, if possible, discourage
the spammer from returning to the site to try again - as much as I
possibly can without resorting to black magic, that is :)

I was thinking that once someone (or a bot) tries to submit a form with
bad input (based on evidence of header injection attempts or html where
it shouldn't be allowed), rather than simply clean up the input or
ignore the request, I could return a 404 header. I was thinking this
*might* discourage them from trying again. What are the chances this
will make a spammer stop coming back to spam this form? (I wouldn't
expect it to stop all spammers, but if it stopped even a few, it might
be worth it.)

-- 
sarah adams
web developer & programmer
portfolio: http://sarah.designshift.com
blog: http://hardedge.ca