An identity linked to another one
Last by expected cost, because it happens to few people and takes no money at all. It is here because it is the only entry that cannot be undone in any sense.
- How often
- Uncommon
- Typical size
- No money at all
- Recoverable
- Never, in either direction
- Cost to prevent
- Nothing, if decided early
What creates the link
| What you reused | How strong the link is |
|---|---|
| A key across platforms | Proof. Anybody holding both public keys can check it, without your involvement, forever. |
| A handle | Strong evidence, and it works retroactively on anything posted under that name years ago. |
| A variation on a handle | Almost as strong. Variations are trivially matched. |
| An avatar or image | Strong. Reused images are matched automatically. |
| Writing style | Weak alone, stronger with volume, and it survives changing the name. |
Why it ranks last and still matters
Expected cost is money, and this costs none. That is the honest reason it sits at twelve rather than higher, and the ranking would be dishonest if it were fudged to make a point.
What it has that nothing else here has is permanence. Every other entry is a number that can in principle be replaced. This one is a fact about the world that stays true, does not decay, and does not require anybody to be actively looking, because search engines and archives do the work over time by themselves.
The decision, made once
A name used nowhere else and not resembling one you use. A fresh key per identity unless you are a vendor with a specific reason to carry continuity, in which case you are accepting a permanent verifiable link and should do so knowingly. Both cost nothing at the start and cannot be bought back later.
The honest limitation: you cannot audit your own history reliably from memory. That is an argument for generating something new rather than trying to work out whether an old handle is clean.
Why the link works in both directions
A connection between two identities is not a fact about the newer one. It joins everything either name ever did, in either direction, at whatever point the connection becomes visible. Something written under an old handle a decade ago becomes attached the moment a shared key, image or phrase ties the two together, and nothing about the passage of time weakens it.
What accumulates without anybody attacking you
- Archives. Pages are copied and kept regardless of whether the original still exists.
- Search indexes. A handle used twice in public becomes a query anybody can run.
- Image matching. Reused avatars are matched automatically and cheaply.
- Your own writing. Distinctive habits survive a change of name, and volume makes them stronger.
None of that requires a person deciding to look into you. It is the ordinary operation of tools that exist for other reasons, which is why the link keeps working long after everyone involved has lost interest.
The vendor exception, stated honestly
A vendor carrying a key between platforms is choosing a permanent, publicly checkable link, and they are doing it for a real reason: continuity of reputation is the asset. That is a legitimate trade rather than a mistake, provided it is made knowingly. What is not legitimate is drifting into it, which is what happens when a key generated for one purpose gets reused because generating another was mildly inconvenient.