Deleted online isn’t really deleted. It’s more like ‘deleted from view’. Unless you are the sole holder of the content on your devices, and you securely erase with multiple passes or the destruction of hardware, it’s better to assume that it will become public searchable data one day.
“Nowadays it’s a bit more different. Now imagine if there would be also a field just like `confirmed` which with 1 would represent yes, that the user is confirmed and 0 would stand for no, he’s not. Just in this case — the field would be named `deleted`, with the completely same principle. With 1 saying that yes, you’re deleted, and 0 showing that you’re active.”