Some are more vocal than others. It's probably not sustainable, IMO. I believe in the future we'll have relays that have user limits or maximum capacities.
Discussion
Also remember (not you Derek cause you know) these are purely text files. Any images, GIFs etc are purely converted by the client, not the relays so luckily duplication makes it not as much as you would think. I think Will spoke about the one he had and it was wayyy less than I thought it would be, being a main relay.