Robots.txt edit caused increase in spammers?

[frostipuff]

I had to change my forum's registration to member approval after a marked increase in penis peddlers, door hangers, and fertility hawkers.

The only thing that's different in the last 24+ hours is I edited my robot(s).txt files after noticing the forum's Print Pages were being indexed in searches, instead of the display page.

Here's the new contents of both files:

User-agent: *
Disallow: /forum/Sources
Disallow: /forum/Smileys
Disallow: /forum/Packages
Disallow: /forum/avatars
Disallow: /forum/attachments
Disallow: /forum/Themes
Disallow: /forum/index.php?action=printpage
Disallow: /forum/index.php?action=stats
Disallow: /forum/index.php?action=help
Disallow: /forum/index.php?action=search
Disallow: /forum/index.php?action=mlist
Disallow: /forum/index.php?action=post
Disallow: /forum/index.php?action=profile;area=showposts;u=*
Disallow: /forum/index.php?action=profile;area=showposts;sa=attach;u=*
Disallow: /forum/index.php?wap2

Am I missing something? Did I inadvertently open the floodgates to idiots?

Short of hacking the code to ban IP addresses before they attempt to join (via StopForumSpam and Project Honeypot), is there anything else I can do to deal with these annoying, and possibly malicious, dweebs?

SMF 1.1.13.

Oh, the robot files are at the root (public_html), but my forum software is installed in public_html/forum

[frostipuff]

Hmm. Never mind. Looks like a spammer epidemic.

I'll look for a mod.

[Aleksi "Lex" Kilpinen]

Two mods that can stop nearly all spammers if combined:

HttpBL For 1.1 and 2.0 &
Anti-Spam Verification Questions for 1.1 (2.0 has this built in)