Hey everyone, I'm so sorry for the issue! It should be fixed now.

We are always proactively working on security improvements, and this issue was caused by a new bot management tool not being optimally configured. It seems to have thought a small number of real people were 'bots' and issued the captcha challenge in response. For those of you that were affected I know how frustrating that was.

Again, it's fixed now and I'm really sorry that it happened.