Anyone using Bitcasa's unlimited cloud storage plans will need to make other arrangements, as the company discontinues the unlimited plans that put it on the map.

Bitcasa says it's upgrading to a new storage infrastructure, and unlimited storage won't be part of it. To keep their data on Bitcasa, unlimited users must transfer to a 1 TB plan for $99 per year, or a 10 TB plan for $999 per year, by November 15.

In a blog post, Bitcasa explained that few people actually need unlimited storage, with only 0.1 percent of subscribers using more than 10 TB, and that it suspects abuse among some unlimited subscribers. "Our Acceptable Use policy has been a challenge to enforce with our privacy features, as we can only see the amount of of data stored--which for some customers, is at a level that seems impossible for individual usage," Bitcasa wrote.

When Bitcasa launched in 2011, unlimited storage was its most noteworthy hook. But the company has since de-emphasized the offering, and last year increased the price tenfold for new subscribers, from $10 per month to $99 per month. Existing users were grandfathered into the original pricing, but now they're being kicked out for good.

Users with tiered data plans also have some hoops to jump through as Bitcasa upgrades its infrastructure. They'll need to login to Bitcasa's website and follow some instructions to load their data, account details and billing information onto the new backend, and they'll have to download a new set of apps. Users who don't switch to the new infrastructure by November 15 will lose their data.

Why this matters: Bitcasa is one of the only companies offering unlimited cloud storage, but couldn't make it work. While it's unfortunate that some people were abusing the system, the decision also strands legitimate users who must now pay significantly more to house their data. Aside from Bitcasa's 10 TB option, the next-cheapest alternative is Google Drive, which charges $99 per month for the same amount of storage.