The numbers that could have come back

Every counter here has a number. It appears in the embed code, in the statistics address, and on however many pages the owner put it. Numbers are handed out by picking a random one between 100 and 9,999,999,999 and checking whether it is already taken.

Checking one table.

The other table

Counters that have not recorded a hit in a long time get moved to an archive table. That is ordinary housekeeping — it keeps the working table small and the queries against it fast. On 24 August 2026 the archive held 212,771 numbers, and not one of them was in the table the generator checks.

So every one of them was free to be handed out again.

Against ten billion possible numbers that is a collision rate of roughly two percent: about one in fifty new counters would receive a number that had belonged to somebody else. And these are not abstract collisions. An archived counter is archived precisely because its page went quiet — but a quiet page is not necessarily a deleted one. If the old embed is still sitting in some forgotten sidebar and that page gets a visitor, the hit lands in a stranger's statistics, on a counter created years later.

We have no way to tell whether that already happened. Nothing distinguishes a hit that arrived this way from any other.

Two changes

The generator now checks both tables. And deleting a counter — which, as of the same day, an owner can do themselves — leaves a tombstone behind: a row consisting of nothing but the number, so it can never be reissued. A deletion removes twenty tables' worth of data in one transaction and keeps no copy, which is the whole point of a deletion; the number is the one thing that has to stay burned.

Why it went unnoticed

The generator was written when there was one table. The archive came later, for a different reason, solving a different problem, and nothing connected the two thoughts. Both pieces were correct on their own.

That is the shape most of these have. Not a mistake anyone made in a single place, but a consequence that nobody was standing in a position to see. The only defence is to go looking on purpose, and the question that found this one was ordinary enough: before building deletion, where else does a counter number live?