What story is that?
The problem with many conspiracies is one question: "how does it work in real life?" In this case:
1. For it to work it violates voting anonymously. The operation would be criminal violation of civil and voting rights perpetuated on millions of innocent voters.
2. The coding is not a tracking device by itself.
3. It needs a reader programed to read it. Supermarket scanners don't read ballots and voting machines don't read what you get from the supermarket.
4. Again, for anonymity, the mark is on the ballot, inside single or double envelopes, so it can't be read unless it is removed.
How it works in real life falls apart immediately.