I'm tempted to try it if it's an easy install, but I fear it won't help. The spammers we're getting these days are obviously actual humans, not bots. They would have as little trouble with these pictures as they do with our Q&As.

What's your forum about?

This is way off topic for this mod, but in the interest of education: The one of which I was speaking is international web hosting, which prevents me from blocking any parts of the world. Another site - a small local community - sees no such problem, presumably because I've got most of the planet blocked off.

We're seeing at least one human a week, maybe two. I just can't imagine they can make any real money at this, especially if they have to make x posts before they can even post their first link. Of course, as soon as the links go up we've caught them.

Ah that is a tough one... even if you made a question "on topic" they would likely know the answers.

However I wold still try this. I was certain I was getting hit with human spammers- but since implementing this my number of obvious spam registrations has dropped significantly.

Remember sometimes human spammers still run scripts and scripts are made around Q&A and ReCaptcha answers... When something new/different comes out like this their scripts just can't deal with it- and unless it becomes popular they may never update their scripts to work with a system like this.

Protection is from the relative obscurity of this mod/system.

If it's a real human going forum by forum one at a time nothing will ever really stop that of course- but a lot of "human" spammers use tools to speed that up- this WILL help against them.

The author's going to have us shot for straying this far off topic (or thank us for the bumps :) ).

Good point. But realistically how often could I change the photos to stay ahead of their scripts? Wasn't there an add-on once that linked to a site where they dealt with this for you? I suppose it must have been a pay site.

I'm the author. ;) And I run an off-topic forum so I'm used to this.

My thought is that this isn't a popular mod, there are no scripts yet.

Installed working on 4.1.10 but Random image not working

Can you explain what you mean by the "Random image" not working?

Did you setup multiple questions?

I have it working on 4.1.10 as you can see in this link:
http://www.qapla.com/mods/register.php

The images appear to be random.

done now random image working !

this is awesome
I will donate you some money once I start making it