Looking at the last few minutes of messages, I get the feeling that all it takes is a handful of motivated (i.e. jobless) malicious individuals to make an entire community or a corner of the Internet look like it has devolved into barbarism.
Don't want strangers to abuse your resources and community and hide being anonymous to avoid accountability? Adjust/tune that aspect of your community - why can't you be creative and try to solve the problem with ideas like how tribes and organisms deal with this in person.
maybe we can evolve chat interfaces for this obvious low-cost-noise age. Increase the cost somehow, not saying I know how, but it is definitely possible to filter out noise by being creative. edit: stay tuned and I'll probably figure out some solutions.