IDrive has all the features you need!

Multiple Device Backup
Multi-Device Backup
A single account can backup data from multiple computers and mobiles

IDrive Snapshots
IDrive® Snapshots
Historical view of data to perform point-in-time recovery; restore up to 30 file versions.

IDrive Express
IDrive Express™
Faster backup/restore of data, via physical storage shipment

Mobile apps
Mobile apps
Backup, access and share files from mobiles using IDrive apps for iOS and Android devices

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*The 95% offer is applicable for the first year only.

Note: The special discount offer applies only to the plans listed here. Upgrading to a higher storage plan will negate the promotional pricing, and the full price of the higher plan needs to be paid.

Deal Here

Can I back up data from other peoples accounts?

I'd think so since it's multi-computer/user ....