Continuing the discussion from Parler… Thoughts?:
There are two cases.
- The data is stored on a drive in your possession.
- The data is stored by someone else.
In case 2, you should assume that you have no legal right to get the data deleted (YMMV depending on country), it is unlikely to be deleted, and even if it is truly deleted, it may be on backups for X years or forever. So the best option by far is avoiding having the data collected in the first place.
In case 1, you can delete the data but watch out for backups.
In the extreme (depending on your personal threat model), physical destruction of the drive is the only option e.g. high temperature incineration - but that may not be a good option if you live in an apartment.
If you are erasing the drive then
shred is your friend. You have the option of multiple randomize passes and an optional final zero pass. For SSDs you more or less have to do multiple passes because of wear leveling - and even then there is no absolute guarantee that all blocks have been overwritten.
In many situations it is a good idea to use full disk encryption / full partition encryption. In that case, it may be sufficient to erase the on-disk encryption info only e.g. much faster - but this remains problematic for SSDs.
An alternative (cheaper and faster) approach is to use a key file on a different medium (in addition to or instead of a passphrase) and then you can physically destroy or
shred the key file. I believe that LUKS also gives you the option of storing the security header on another medium, which would lend itself to a similar approach.