user registeration form without captcha?
Hi, I was trying to sign-up Twitter today and I noticed that their registration form does not have a captcha. The form URL is https://twitter.com/signup. I also noticed that they used an input like below. <input name="authenticity_token" type="hidden" value="ce803cee65a96aaa97bdf75da166599c3adc9ec8" /> what kind of method is this? D...