AFN actually uses Captcha for our new user registrations. If we don't, we see a world of spammers trying to join the site (we still manually approve all accounts on top of everything because they still get through from time to time.) I understand there's pretty much always another option or "better" way to do things, but sometimes there's a reason for using the "status quo," not just out of convenience, but because they successfully work for the purpose they are intended for without needing to spend an arm and a leg. Not to downplay the security aspect of it, but the likelihood of someone using Captcha to "sniff out" growers so they can steal from them seems a bit "out there."
I live in Colorado, I'd have an easier time taking a walk down the alley and looking for the first fence over 6 feet tall if I wanted to be a crop thief.
Based on the assumption that everyone involved in cannabis has a huge team, developers, or piles of money (which many of us do not.) Don't forget that common sense goes a long ways when posting about cannabis online (and that's free!) We've removed dozens of images from here over the years because someone forgot a box or letter was on the table with a postal address, etc.