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this post was submitted on 28 Aug 2023
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Was going to say the same. Windows and Linux both use “lazy” ways of deleting things, because there’s not usually a need to actually wipe the data. Overwriting the data takes a lot more time, and on an SSD it costs valuable write cycles. Instead, it simply marks the space as usable again, and removes any associations to the file that the OS had. But the data still exists on the drive, because it’s simply been marked as writeable again.
There are plenty of programs that will be able to read that “deleted” content, because (again) it still exists on the drive. If you just deleted it and haven’t used the drive a lot since then, it’s entirely possible that the data hasn’t been overwritten yet.
You need a form of secure delete, which doesn’t just mark the space is usable. A secure delete will overwrite the data with junk data. Essentially white noise 1’s and 0’s, so the data is completely gone instead of simply being marked as writeable.
Would rm be okay if you regularly fstrim?
No, fstrim just tells your drive it doesn't need to care about existing data when writing over it. Depending on your drive, direct access to the flash chips might still reveal the original data.
If you want ensure data deletion, as OP said, you'll need to zero out the whole drive and then fstrim to regain performance. Also see ATA Secure Erase. Some drives encrypt by default and have Secure Erase generate a new key. That will disable access to the old data without having to touch every bit.
Or physically destroy the whole drive altogether.
From: https://en.m.wikipedia.org/wiki/Trim_(computing)#Operation
So: probably yes.