The BIGGEST mistake in the history of the public internet was in letting Marc Andreesen get away with adding the IMG SRC tag to NCSA Mosaic in 1992/3-ish.
The second-biggest mistake was allowing browsers to automatically load all images in a web page.
In both cases, the perpetrators should have been tarred and feathered, publicly mocked, then tarred and feathered again until they repented.
We should ban video from the public internet. It's the only way to be sure.
@ysbreker @cstross Programmers by and large share the general ignorance of systems under selection.
Email begets spam because the cost to send an email is zero; if you can make any money by sending email, it drowns.
If you want to make the thing work, you've got to acknowledge selection and build it so anti-social behavior rapidly acquires intolerable costs without building it so that it's a machine for enforcing normalcy.
What we've got is a machine enforcing the normalcy of advertising.
The biggest cost, in Germany or otherwise, is the people who do the talking to the callees. It dwarfs the costs of RTNR and suchlike.
That has long since (i.e. decades ago) been optimized, both by mechanizing the Hell out of the call filtering process and enabling remote operations where labour costs are cheap; and mass telephone calling is really not a counterexample to the claim that expense makes such things difficult.
Indeed, what has happened, rather, is that a demand for outbound call centres has given the world cheap off-the-shelf set-ups for this stuff, complete with everything from answer 'phone detection to agent activity/performance tracking.
@bithive Spam phone calls hereabouts don't necessarily originate from licit network endpoints.
More formally, spam email has zero incremental costs; once you're connected to the network, spam email n+1 is functionally free.
Setting things up so you can't tell who said that and can make spam intolerably expensive to send is hard.
(Police are a major nexus of domestic abusers and you want someone being assaulted to be able to say so and get help truly anonymously.)
Charlie Stross
ysbreker
Graydon
BitHive 
JdeBP