I've learned about SpiderOak in a [reddit discussion](<a href="http://www.reddit.com/r/technology/comments/1idagr/snowden_leak_microsoft_added_outlookcom_backdoor/cb3kwg5" rel="nofollow">http://www.reddit.com/r/technology/comments/1idagr/snowden_l...</a>). Worthwhile starting an own thread.