A little paranoid, aren't we? I don't think that being an Amiga fan and related info is something abusable, I would rather be worried about other places that require you to enter your name...
You must be excessively naive. Who is minimig.net? You don't know, anonymous registrar (below). Why do they need your name and email to locate you on a map? They don't, so why are they collecting that information - you don't know. How is the data being stored? Who has access to it? You don't know.
You might as well print out flyers with your name, address and email on them and toss them about town.
Domain Name: MINIMIG.NET
   Created on..............: 2008-11-30 19:18:06 GMT
   Expires on..............: 2010-11-30 19:18:08 GMT
   Last modified on........: 2009-07-17 13:09:26 GMT
Registrant Info: (FAST-12785241)
   Attn: minimig.net 1,500 GB Space and 15,000 Monthly Bandwidth.
   BlueHost.Com INC
   1958 South 950 East
   HOST UNLIMITED DOMAINS *FREE*
   Hosting plans starting at ONLY $6.95 per month -
   Provo, Utah 84606
   United States
   Phone: +1.8017659400
   Fax..: +1.8017651992
   Email: 
whois@bluehost.com   Last modified: 2009-06-08 20:51:44 GMT