In short

Meta connects accounts through a family device ID shared across Instagram, Facebook, Messenger and WhatsApp, plus hardware IDs, IP history and login artefacts. Enforcement propagates across the graph. Breaking the link requires separate hardware IDs, separate storage and separate IP history — not just a different proxy.

The family device ID

Meta apps share a single device identifier through a common SDK. Installing Instagram and Facebook in the same environment links those accounts permanently, regardless of what proxy each one uses. This is the most common way operators link accounts without realising it.

What else feeds the graph

  • Android ID, GSF ID and advertising ID, retained long after an account is deleted.
  • IP history — accounts sharing an IP within a rolling window are treated as related, sometimes months apart.
  • Login artefacts: device tokens, cookies and session identifiers. Reusing one is the fastest possible link.
  • Media hashes. Uploading the same image from two accounts creates a weak but real edge.
  • Contact-book uploads, if you ever allow them. This is the strongest edge of all and it is entirely avoidable.

How enforcement propagates

When Meta disables an account for a serious violation, it walks the graph outward and applies scrutiny — not always a ban, but a trust-score penalty — to connected nodes. This is why you lose accounts in clusters and why the cluster is usually exactly the set of accounts that shared one device.

  1. Separate hardware identity per account: IMEI, serial, Android ID, GSF ID, advertising ID, MAC. All of them, not some.
  2. Separate storage sandbox so no token, cookie or cache entry is reachable across identities.
  3. Separate IP history, ideally a carrier IP that never serves another identity.
  4. Never installing two Meta apps in the same identity unless the accounts are meant to be linked.
  5. Never uploading a contact book.