Marti's one of those people who have decided that a specific seat is theirs, and object to anybody else sitting there. You know, it's funny how the protection of one's preferred location for worship is one of those very few instances where people come over all un-English. Maiden great-aunts who would not normally say "boo" to a goose will stab people with curare-tipped hatpins to claim their favourite seats.
In general, this process is the best-practice in a standard customary-worship-seating-appropriation-related incident:
And so she decided to put a little notice on her seat. It was very polite. It said "This is Marti's seat. It is protected with Smart Water. If you sit here, you will be hunted down and punished severely."
The trouble was, some people didn't believe her. And the beatings she would administer would maybe have a retrospective effect, but would only really be a deterrent to those who were not newbies. The other problem we had was that she was endlessly testing people's bottoms for the specially-labelled chemicals in the water. And that could be quite embarrassing.
She suggested the use of a radioactive marker - because she could use a Geiger counter at a distance, with less sensitive handling of the evidence required. But we vetoed that one on the grounds that it might be contravening the Geneva Convention.
So she's gone for the preemptive approach. We don't like it. It spoils the ambiance of the Moot House. And it takes a lot of care and attention. But the rottweiler is certainly effective at keeping other people from sitting on Marti's seat. She daren't try and sit there herself now. That dog's terrifying. But at least nobody else has her seat.