I am also a Mozy user, and was quite shocked when I read the email this afternoon.
I'll be canceling my subscription soon, since I'm in a month-to-month model, and my monthly payment would skyrocket!
I can deal with a slight price increase, or even an OPTION to give users unlimited space, but no... instead, they start with a 50 GB plan and rise the price.
Now, I understand about the bandwidth costs, limits and caps... I've been managing my usage for the past few months to avoid going over the limit with Comcast (250 GB, S FL)
It's true that we are backing up more and more, and files are growing in size, but hard drives and Internet pipes have also been adjusted to somewhat compensate for that... Storage is extremely cheap these days. The "storage cost" line isn't such a good reason.
Oh well, I'll be canceling my plan soon, and continue to back-up to an external hard drive while I find another unlimited and well-priced off-site (cloud) back-up solution.