A certain troll/spammer/the human manifestation of AIDS has recently exploited the fact that, if you send a long message without any spaces in chat, the page can be stretched. This doesn't affect people on the chat on computers that much, all it does it add a scroll bar at the bottom of the screen (which, honestly, probably annoys me more than it should), but on mobile, it stretches the page. I remember a while ago, walls used to be able to be stretched, and it was fixed so that when a long message was posted, the post would get a scroll bar on that. I'm not sure if you could do something similar with chat messages, but, even if you could, I personally think that it'd be a bad solution. I'm not sure exactly what you can do in terms of fixing it, PM, but if you can, some solution might be to prevent posts with long strings of characters without spaces from being sent, similarly to how profiles work.
TL;DR: Long strings of characters without spaces can stretch the chat, and it'd be great if it could be fixed.
Something else I should add: The aforementioned guy has been a nuisance on chat for the entirety of this year. Fizz has banned his accounts multiple times, but he doesn't seem to intend on slowing down. It'd be very helpful if you could block a range of IPs, PM.