The main part relevant to this problem: responding to many stalkers even with negative / threatening behavior is a form of positive encouragement, and they'll keep at it. The only solution is to filter YOUR experience (delete / don't listen to VM, don't read emails etc) rather than trying to get the unwanted inputs to stop.
That way there's no feedback to the jerks on the sending side, they get bored or angry at someone else, and go away.
One subtlety is: don't turn off your phone, or leave a outbound message saying 'I will not be checking this voicemail because of the jerks". That's encouragement. Change nothing. Get a 2nd phone as needed, use that.
Likewise, don't setup an autoresponder saying "I don't read this email because of the jerks" - same logic as above. GoF is a very worthwhile read, for everyone.
Every couple of weeks, someone would dig up a cable in the street (causing an outage), or the power would go off for a long time (and our UPS would die, and that would cause an outage), or someone would trip over something (causing an outage).
Grrr. We eventually moved our stack of mac minis (cheap! and low hassle) to a specialist colocation place in Las Vegas that basically is a sub-tennant of the gigantic Switch datacenter.
Here was the surprise bonus - in addition to way better uptime, the quality of the connection we got was SO good it was crazy. Doing a 500Mb system update takes like, a minute to download. And because we didn't need the fancy Symmetric DSL connection back home, we could save money by downgrading to a regular ADSL connection. And, we got a 'naked' / all ports open connection to the net without hassles.
This was a seriously Good Move for us - think about moving your box somewhere offsite. It's cool.
If you happen to be using Macs, we used http://macminicolo.com/ (we're just a customer, but a pretty stoked one).
The Tao is like a glob pattern: used but never used up. It is like the extern void: filled with infinite possibilities.