Well, the main "danger" is that you could be directed to
a site other than the one you felt safe giving your data
too. If you hit a post to Amazon's order form and the last page
redirected you to Barnes and Noble's page for the purchase.
Worse, if the error document of the site was "tweaked" and
the CGI removed you might wind up pouring your data into someone
else's logs.
Also, please don't confuse redirect AFTER post with redirecting THE post.
You shouldn't be conned into sending data to someone you
didn't expect. Where the browser goes after the data is
received properly is something else entirely.
Read for yourself: RFC 2616 Sec 10.3.2 and
and you might look at most of Sec 15 as well.
--
$you = new YOU;
honk() if $you->love(perl)