whois weedseeds.ie
% Rights restricted by copyright;
http://iedr.ie/index.php/mnudomregs/mnudnssearch/96
% Do not remove this notice
domain: weedseeds.ie
descr: benjamin bennett
descr: Sole Trader
descr: Discretionary Name
admin-c: AMN836-IEDR
tech-c: ABG704-IEDR
registration: 03-March-2011
renewal: 03-March-2013
status: Active
nserver: ns1.db-group.info
nserver: ns2.db-group.info
source: IEDR
person: benjamin bennett
nic-hdl: AMN836-IEDR
source: IEDR
person: Lets Host Domain Services
nic-hdl: ABG704-IEDR
source: IEDR
So, now you have a name.
Next, you send them an email with a web beacon embedded in it to get their IP address. Using Traceroute you can get a good idea of where they are physically located or at least a city. You then begin searching business filings, property records etc. to narrow it down.
Once you have found the location you check for any sort of wireless internet which they might be using. You hack this to verify that they are in fact the guilty party. The rest is easy. Use their internet to send threatening letters, do a spoofed voip call to the police telling them that there is a robbery, hostages, men with guns. Or just lock them in the building and set it on fire.
Or, if you have the ability to travel in time, go back in time before they made the website and kill them so you never give them money to begin with.