Personas merge protection algorithm protects your identity graph from unnecessary merges by finding and removing untrusted external IDs. Here's an example:
In this example,
anonymous_id: a1 is not reset during a
User Logout. Without merge protection, we'd merge user_id u1 and user_id u2. Instead, our Merge Protection algorithm detects that such a merge would break user_id uniqueness and prevents the merge.
This is especially helpful for preventing "blob users" that are merged together by non-unique anonymous IDs or by common group emails like