Before letting an AI act on your files: back up with the 3-2-1 rule
STOP stops an AI; it does not undo what is done. A backup is the real way back: the 3-2-1 rule recommended by the CNIL, applied simply on Mac and Windows.
When an AI sorts, renames or edits your files, mistakes remain possible: a misunderstood instruction, an overwritten file, an emptied folder. STOP halts what comes next, but does not undo what is done. The only real way back is a backup. The CNIL devotes sheet 17 of its personal data security guide (2026 update) to it.
The 3-2-1 rule
The CNIL presents it as the state of the art: 3 copies of your data, on 2 different media, 1 of them offline. It also recommends keeping a copy in another place than the computer, encrypting backups and regularly checking that you can restore them.
In practice for a small business
- Copy 1: your files, on the computer.
- Copy 2: an automatic backup to an external drive: Time Machine on a Mac, File History on Windows. Unplug the drive once the backup is done: that is your offline copy, safe from ransomware as well as from an unfortunate command.
- Copy 3: an encrypted backup off the premises, with an online service or on a second drive kept elsewhere.
Sync is not a backup
iCloud Drive, OneDrive or Google Drive copy your changes everywhere, including a deletion or an overwrite. Their recycle bin and version history can help, within their time limits, but they do not replace an independent copy. The CNIL warns precisely against backups kept on the same system as the data, without isolation.
Test the restore
An untested backup is a promise. Once a month, restore a random file into a temporary folder and open it. Five minutes are enough, and it is the mistake the CNIL names first: discovering on the day you need it that the backup is unusable.
Before each session with an AI
- Check the date of the last backup: less than 24 hours.
- For a bulk operation, have the AI work on a copy of the folder.
- Keep STOP within reach, and check the result before deleting the copy.
What SteerLatch does, and does not do
SteerLatch connects your AI to your computer; your files stay there, and SteerLatch keeps no copy. So it does not back up your files for you: backups remain your responsibility, with your system’s own tools.
Read also: giving an AI the terminal: 7 habits and STOP, consent and revocation.