Quick answer
Use a shared system with per-user permissions (NAS or cloud) instead of email/USB drives — that way you always know exactly who has access to what, and can revoke it instantly.
Email and USB sticks are the most common way business files leak — not out of bad intent, but because you lose track of who has which copy.
The problem with email/USB
Once you email a file, you no longer have any control over it — you can’t revoke access if someone leaves the team, or see who opened it.
The right approach
A central system (NAS or cloud storage) with per-folder/per-user permissions lets you grant exactly the access each person needs — and revoke it instantly when needed, without wondering where copies still exist.
- Access permissions per person/team
- Instant access revocation when needed
- History — who opened/changed what