How do you protect yourself from a similar fate? The way I do it is by managing all of my data locally on my laptop (and of course making religious, at-least-once-daily backups of said data). I download all my email using POP3, from a VPS that I am paying for into fetchmail / procmail / mutt on my laptop. My address book is managed locally in a YAML database, and my calendar is managed using flat text files and Remind. Note that none of this precludes remote access to my data, either; I carry a copy of PuTTY on my USB drive, and with the appropriate SSH key and/or S/Key password I can access my data, securely, from anywhere in the world.
That's just one way of going about it, of course; you don't have to go all Unix-retro to achieve the same peace of mind. The theory is simple: just find a way to consolidate the master copies of your important data on machines that are physically under your control, and then make frequent backups of these machines. If possible, also make sure that you have some sort of service agreement with the servers you rely upon for email, Web service, XMPP, and so on. Yes, it is more expensive, and yes it's more difficult than just signing up for a free GMail account, but your data is worth it.