[trotsky]

de-duplication is the process where if two customers both store the same file, say abbey_road_from_itunes.mp3 the service provider only needs to store one copy of it. They can't do this if they encrypt each copy of that file individually for each customer. This adds up to a lot of space for a service like this, as most of the large files people store aren't their own creations.

[bricestacey]

Doesn't deduplication make them vulnerable to MAFIAA lawsuits?

[trotsky]

It shouldn't - I'm sure they qualify for Safe Harbor as long as they respond reasonably to DMCA notices.

[Dylan16807]

Also, two people can have the same file but only one permission.