From what I understand, many websites now use "soft deletes", where they cut out the ability for users to see/modify data. It remains intact on their servers though.

I really don't agree with this, but I can't deny that there's value in this data. It's unscrupulous to hold onto it, though.

In my opinion, there should be some way to hard-delete information like this, even if the user has to go through some two-key-nuclear-launch confirmation process to prevent accidental deletes.