This is actually why i took so long to launch the site. I've used the prototype version of this for a long time. The app is written in node so it is incredibly fast, like destroy the internet fast. That is why email confirmations are required and accounts are limited to 5 crons each. I will add a captcha on account confirmation shortly as well.
Alternatively you could get the user to validate ownership of a domain, i.e. if you want to run jobs at http://foo.com/something, tell them to create http://foo.com/cronio.txt with specific contents.
This is actually why i took so long to launch the site. I've used the prototype version of this for a long time. The app is written in node so it is incredibly fast, like destroy the internet fast. That is why email confirmations are required and accounts are limited to 5 crons each. I will add a captcha on account confirmation shortly as well.