Stay away!
I paid $7 for 5TB of backup and they charged me for more than $1,000 for what they claim to be overuse without any warning!
After several session with iDrive support team they've finally admitted that there's a bug in their system that miscalculates the amount of data that's being backed up.
Their billing team promised to refund me for the charge but I didn't get any refund and they're not responding to my Emails.
Worst service I've ever experience!
There are much better online backup services with much better support.