A report from Apple that 85 million people have signed up for its iCloud service is an indication a significant number of computer users are willing -- even happy -- to entrust their personal data, from documents to music to last summer's vacation snaps, to other digital hands.

While not a new concept, Apple's iCloud and its undeniable success shows the extent to which people are willing to trust "the cloud" -- servers in a dedicated facility possibly thousands of miles away -- to hold their data, not as a backup of what's on their own hard drives but as the sole repository of their digital lives.

In addition to Apple's offering, Microsoft says 17 million people a month use its SkyDrive service, and Dropbox reportedly has more than 50 million users.

Similar cloud services for users' music are available from Amazon and Google, all a part of a "cloud" trend that seems unstoppable.

Of course, before the phrase "cloud computing" was coined, off-site data storage was widely available, although it was normally considered a "belt-and-suspenders" form of backup of material users held on their own computers.

The difference with the cloud is that many people seem confident enough in it to make cloud storage of both their important data and their applications the only versions, calling programs and files up on their computers, tablets or smartphones when needed but surrendering them back to the cloud when they don't.

While trust in the cloud seems present and growing, some of the qualities and technologies behind cloud computing present potential difficulties for individual users.

First and foremost is that cloud computing requires a dependable Internet connection. With so many people now working from their homes, this can be a problem, as even the most reliable ISP's will have down time occasionally. If your programs and data are on your own hard drive, you can keep working until the problem is fixed. If not, however, no Internet means no cloud; no cloud means no work.

And even with a working Internet, cloud computing can be slow, getting in the way of desired workflow. Programs and files can load more slowly than if they were being accessed locally, leading to frustration.

And of course there's the question of the security. Cloud service providers all claim enhanced security because data is replicated across multiple machines.

In the end, it will come down to trust -- and to what users want.

Apple Chief Executive Officer Tim Cook has said he has no doubt what they want.

"I see it as a fundamental shift, recognizing that people had numerous devices, and they wanted the bulk of their content in the cloud, and easily accessible from all of the devices. I think we're seeing the response from that, and with 85 million customers in just three months, it is just not a product. It is a strategy for the next decade," Cook said.

Many users seem willing to take that -- on trust.