My main reason for client side is to skirt legal troubles that can result from running a web-filtering proxy (not whether it's legal or not, but whether you will be in legal fights). Either way, needs to be as transparent as possible and as usable by the less-tech-savvy as possible.
But that's really all it is, a web server (or an app, or an extension, or a combo) that serves you up the web looking like Craigslist. Would require strongly curated set of "fronts"/"recipes".
In the process, it would also decentralize communities and establish digital equivalents of coffee shops (i.e. places to work in public and meet strangers)--basically SDF, but deployable on Raspberry Pis with more modern userland toys (i.e. software actually designed to be multi-user on the same system).
[1] https://en.wikipedia.org/wiki/Gopher_(protocol)
[2] https://en.wikipedia.org/wiki/SDF_Public_Access_Unix_System