NetSerializer does not handle these well and sends the entire backing array instead of a more compact representation. This can then cause it to start sending lists of length 1 with a *capacity* of 4096 resulting in 250 KiB/s down to send updates for a single entity. As it just did on the public server...
Clients would treat any message coming in as being from the server they're connected to, instead of ignoring them if they're not correct.
This made the client crash inside integration tests because messages came in while disconnected.
This fixes that.