I've asked for similar, but the board isn't geared up for it. It does require proof you're not a robot when you sign up, but this is circumvented by crowd sourcing registration. TBH, it's flipping pointless, however, they don't care.
I've had a few days off for a little get-together in Manchester called Sparkle, so there were a few more than normal.
There are ways and means around it, but Spammers are ingenious, so I clear the Spam each morning, and when we get a Spam storm, the board is taken off-line while new security measures are put in place that work for a few days, then they start to come back in dribs and drabs.