Another cloud service is no longer unlimited. Amazon ended its Unlimited Everything plan.
As Amazon announced today in this FAQ article, new customers have to chose between a 100GB plan for $11.99 per year, or the 1 TB plan for $59.99. Up to 30 TB of storage are available for an additional $59.99 per TB per year.

Amazon is now providing options for customers to choose the storage plan that is right for them. Amazon will no longer offer an unlimited storage plan.

But the change also impacts previous subscribers.
Just like Bitcasa, Pogoplug and OneDrive before, current ACD subscribers will have to choose one of the new limited plans when renewal time comes rolling.

For Amazon Prime members, photo storage is still unlimited, and all Amazon customers get 5GB free.

This change comes in the wake of the ban of several ACD software clients - rclone and acd_cli - that allowed ACD users to mount their storage as a disk on Linux or backup encrypted data, without having to use the mediocre official Windows/MacOS Amazon Cloud Drive client.

Users who are over-quota at renewal time - meaning their ACD account contains more than 1TB of data - will have a 180 days grace period to download their files, delete files over quota, or upgrade to a bigger and more expensive plan. After these 180 days, Amazon will start deleting the data over the quota, starting by the most recent upload.

Unlimited storage offers are now harder to come by.
For unlimited backup, you can try Crashplan or Backblaze.
For unlimited storage, Jottacloud can be a solution. SpiderOaks also sometimes has a special offer for unlimited encrypted storage for about $150 per year.
If you are ready to compromise on speeds, HubiC offers a 10TB storage plan for 50€ per year. Unfortunately, HubiC speed are limited at 10Mbps both up and down.
Finally, if you have a domain name, G Suite from Google offers unlimited storage for $10/month per user. If you have less than 5 users on your domain, there is a 1TB storage limit, but it is not currently enforced. However, abuse from /r/DataHoarders could negatively change that.