This is probably a bit late for some people, but it may help others.
Do NOT let Origin store your payment details! Please go double check that you do not have any stored payment details in Origin, or on the website: http://store.origin.com
Also please enable login verification (via the web site, not sure if you can do it in the client) - this will request a one time password from unrecognized devices.
There are lots of reports of Origin accounts being hacked, and unauthorized purchases being made. Although you can request Origin to refund the purchases, there have been reports of accounts being banned (notably after refunding purchases of FIFA), and then Origin support being unresponsive with queries.