Just throwing this idea out there as it seems to be happening a fair amount.
Not just on FFRR, but on DEF2 and some other forums run by Martin.

Is it possible to have better forum security when you sign up?
Like a human test where you have to choose the profile of a Range Rover or something?

The amount of spam seems to be increasing quite a bit. Presumably the spam-bots are getting more advanced.

PS. Short term - assigning another mod would help!

I'm dealing with this, unfortunately they've picked the exact time I'm on holiday so I'm doing the best I can.

Bear with me.

New registration security measures are in place.

so what was the reason for all these 50 odd dodgy registrations?

Looks like the 3rd party security features the site was using (reCaptcha, owned by Google) has been comprehensively broken and can no longer be relied on.