I understand this is something that probably more of our users worry about, so I will add it to our payment page for future reference. I normally teach coding workshops to kids 12-17 using C9 but I found out today during my workshop that you require a payment method in order to make an account now.
This unfortunately renders my regular curriculum a little bit broken and forcing me to adapt another IDE such as Codepen.
There are plenty of ways to validate the identity of users without asking them for a credit card.It seems like that would meet your needs without excluding younger users. I would like to respond to the part where you mentioned that storing the credit card information is a liability and therefore not the best verification method: We as Cloud9 do not store any credit card information.This is done through a third-party payment system, which meets all the legal requirements for storing such data (also known as PCI compliance).Ultimately, abusers are a distraction that slow progress on highly requested IDE features, which isn't good for legit Cloud9 users.The reactionary measures we've put in place are good but we now require credit cards to prevent abuse from the start. In that to demonstrate how to set up a Cloud9 account to my class I did in fact set up a second free account.