Several addresses at once, and what switching costs you.
Addresses here are not permanent and are not meant to be. Understanding why removes the panic when one stops working.
Those fifty six characters are a public key rendered in base32. Nobody registered them and nobody can revoke them, which is the good part. The consequence is that changing an address means changing a key, and that is a deliberate act with a cost, so it happens for reasons rather than casually.
An address that has absorbed a sustained flood keeps attracting it, because whoever aimed at it already knows where to aim. Retiring it and publishing a replacement resets that. Operators also rotate on a schedule so that no single address becomes the one everybody has bookmarked, which would recreate the single point of failure the set exists to avoid.
Nothing, if you kept the list. Everything, if you kept one favourite. A saved bookmark to a retired address produces a not found error, and the not found error is what sends people to a search engine, and the search engine at that moment is where the copies are waiting.
An outage takes every address at once and clears on its own. A rotation takes one address permanently while the others keep working. If two of three still answer, nothing is wrong and you simply have a stale entry.
Open this page once a month while everything is working and compare it against whatever you have saved. It takes seconds when you are calm, and it is the only version of this task that is safe to perform. Doing the same comparison during an outage means doing it under pressure with a search box open, which is the situation the habit exists to prevent.
Anubis Market