One solution to this is to only read replies from "safe" relays.

We don't have enough safe relays.

The meaning of safe can vary from person to person, but we need more alternatives. For example, micro-relays intended to be used by groups such that they will automatically ban people who have been muted or reported by other members of the same group.

We also need clients that take an instance on deciding where to read replies from, instead of the weird behavior of some of the existing outbox-capable clients that try to "fetch all replies possible and imaginable to any note" (but I'm sure this kind of behavior is also desirable by some, that's why we need different options or toggles).