I do. I encrypt any sensitive information (such as bank statements) my side, then upload when uploading to a service that doesn't encrypt client side. I used to be an advocate of Bitcasa until they sca-roooooed their customers over.
Good point on the Dropbox SS, although their capacity pricing is outrageous. I don't class them as a viable storage solution.
Mine is encrypted on the client side, provider does not hold or retain the keys, and I always use the installed client to upload/download. Only downside is you best not forget your password as data retrieval is impossible without it or the master key.
All the Mac`s are on secure L2TP VPN, when on the go I don't connect to public networks, I use a MiFi with cellular connection. Over the years several of my colleagues have suffered from identity theft and or fraud which is obviously a serious headache to deal with especially when you are abroad and working.
Thx to OS X and a little common sense I have never had an issue, nor is it likely

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