Filtering content at the ISP level is complete fantasy. As soon as you try opening the content of an IP stream to spot what is a T&A jpeg vs. a Ansel Adams picture, there’s no way in Hades you can maintain any sort of bandwidth. Zippo, nada, zilch.
The speed of packet switching in the modern IP network rests on the premise that we don’t need to dig too deeply into the content of each packet. Right now, things like routers and switches are looking only as deep as the TCP header, and that’s pretty rare. Most of the time they’re doing nothing more than the IP header. The content that these idiots want to filter is deep within the TCP payload - and the TCP payload could be split across multiple IP frames, which would require that routers (either the WiFi routers, which are usually really anemic in CPU and memory) or the access routers that are feeding the WiFi routers, re-assemble TCP packets to re-form the payload so it could be inspected.
I’ve worked on devices that have done this for security applications - things like stateful intrusion detection boxes. They can handle perhaps a 100Mbps ethernet worth of bandwidth, but they’re looking for a series of “attack signatures” that requires they look at only a few bytes here or there.
Filtering out video/picture/audio content on a TCP session.... no way. This ain’t like TV or radio, where it is a one-way stream.
Can it be done? Yes, if you give me an nearly infinite budget for R&D, bleeding edge hardware, rack upon rack of CPU, etc. If I’m giving away the service and charging for only the advertisement(s), there’s no hope for ever recovering this level of investment. Ad-based revenue works well when you have something like Yahoo or Google, and you have very little incremental cost per user. When you’re inspecting everyone’s TCP stream for throbbing naughty bits, you have a substantial increase in hardware requirements for every single user. There’s no way that you’re going to get enough out of each incremental user from ad revenue to offset the infrastructure costs.
Now, even if we could do it, do you want it done? Absolutely not. Once the technology for inspecting every TCP payload exists, the Feds could be monitoring everything everyone does on line in real time, every day, all day.
The best way to keep kiddies from viewing porn on the ‘net is for their parents to re-discover a razor strop and learn how to use it on Little Johnnie.
You're forgetting that IP isn't everything. The DNS lookup starts everything, so why aren't DNS servers bogged down? OpenDNS will filter adult content at the DNS level already.
I’ve worked on devices that have done this for security applications - things like stateful intrusion detection boxes.
I'm sorry, but adult content blocking is a lot easier than intrusion detection. It doesn't even require any more than one state. Even if you're imagining some sort of complex computer vision AI that would detect porn, it wouldn't need to be doing it in real-time. You seem to be imagining a serverless internet without common content. For the most part, a user will enter a url that must be resolved by DNS, that displays roughly the same content as it did months ago.