PS: Ask pg to delete your post.
Mass. Rule 4: http://www.lawlib.state.ma.us/mrcp4.html Federal Rule 4: http://www.law.cornell.edu/rules/frcp/Rule4.htm
Did you receive a summons or was it just a printout of what we saw in the TC article? Insufficient service is grounds for dismissal. The plaintiff has time to correct, though.
You should see if there are any users in Delaware. If not, I doubt you can be compelled to court there. Even if you do have users in Delaware, it is a stretch.
For everyone on YC News, this is a reason to incorporate in your home state, not Delaware. Incorporate in Delaware if you want VC funding. Otherwise, stay in your home state. If you incorporate in Delaware, or any other state for that matter, courts automatically grant personal jurisdiction in that state. Basically, that means you have to go to court there.
This is also a reason to incorporate. Right now shimon is personally liable for damages, if any.
If you are making something for others to use, incorporate. It will cost you a few hundred dollars per year in filing fees, but that is just a type of insurance against times like this.
I'm not incorporated and haven't thought about Delaware in particular as a place to advertise Voo2do. There are certainly Voo2do users in Delaware (and in most other places in the world).
The only income I've received to date from Voo2do has been donations from people who found it useful. If you consider the cost of the hosting, Voo2do has been a net money loser for me for many years. But it's led to a lot of other great contacts and given me a lot of satisfaction from helping other people.