You could use rsync and s3cmd in tandem to create a decent backup solution. Of course, it does require the command line and some scripting chops, but I've done it in the past to keep daily, weekly, and monthly logical MySQL backups on S3.

which is a good thing.

if a few years ago somebody said "just copy all your private data to some place on the internet... but encrypt it first" you would take it for the crazy argument it is.

What do you think is crazy about it? If it's encrypted, it can't be read. If it's on "some place on the internet", it can only be as redundant or more redundant as any other offsite solution.

> "If it's encrypted, it can't be read. "

Yet. It can't be read yet.

Any agent capable of ever reading AES encrypted files with 256 bit keys is also an agent capable of opening your safe deposit box, requesting your tapes from a data vault provider, or coming over to your house with a rubber hose.

Short of a vulnerability in AES (in which case we have more problems than a few copies of the Anarchists Handbook in our backup files), cracking proper encryption is simply not feasible.

What about in 10 years, 20, 50?

With arq there are multiple layers that would have to be broken to get to the data. Still a risk, obviously - and one worth considering. I bet in the scheme of things though there are much easier ways to access this data available now.