I guess you could make sure each signed tweet starts with a YYYY-mm-dd HH::MM::SS (TZ) line by itself. At least then a reused old message would look weird beca

I guess you could make sure each signed tweet starts with a YYYY-mm-dd HH::MM::SS (TZ) line by itself. At least then a reused old message would look weird because the time would be wrong, and easily visible (but also easily ignored in the common case, which is probably what is wanted).