rgrenaderphoto Loc: Hollywood, CA

Dropbox spends $53 million yearly on data center infrastructure.
Google, Amazon and Microsoft spent $20 Billion on Data Center Real Estate alone. Google's investment on server infrastructure is running on in the $20 Billion per year range.
Total US Investment on Cloud Computing infrastructure is about $162 Billion.

Is that secure enough?

DirtFarmer Loc: Escaped from the NYC area, back to MA

I don't trust the security of cloud storage either. Nor do I trust the security of the individual external hard drives which hold my archives. A lot of people swear by M-disks, but I wouldn't trust them either for the long term.

I use both individual external had drives and cloud storage for my archives. Although neither is 100% fool proof (I believe the best you can ever do is fool resistant), The combination increases security.

I used to depend on three external hard drives. One was on my computer, one was somewhere else in the house, and one was in my barn about a mile away. I figured a power surge could get my computer and the connected drive, and the one elsewhere in the house could cover it. If the house burned down and got both of those, the one in the barn could cover. But then I decided one mile wasn't far enough away, or distributed enough, so I signed up for a cloud service. Not only does it automatically save new and changed files, it saves them as versions so if one file gets corrupted, the corrupted file gets into the archive, but there's a previous version in there to go back to. I may lose some work, but not all of it.

If you are storing your files only locally, the thing you have to consider is maintenance. Technology changes. Hard drives may continue to work for a while, but not forever, and stuff written on disks is wholly dependent on having something to read the disk. When (not if) technology gets past the disk to something else, you had better transfer all the stuff you have on disks to the new medium. One advantage that the cloud storage has is that (assuming you pick a good company) they will take care of that for you.

dsmeltz Loc: Philadelphia

Do I trust the Cloud 100%? No.
Do I trust my computer's SSD drive 100%? No.
Do I trust my two external drives i keep at home 100%? No.
Do I trust the external drive I keep off site 100%? No.

Do I trust the combination of all four 100%? No, but 99.999%, Yes I do. There is always the 0.001% user screw up possibility.

aubreybogle Loc: Albuquerque, NM

I must confess, those are impressive numbers, I will keep an open mind, but for now....