This is totally absurd.

I agree with many of the replies here saying that this big guy is trying to bully you out of your domain name and most probably acquiring your domain for their use (because of the s in your domain? Give me a break man...)

Imho, you can settle it through a combination of the helpful solutions offered by our fellow forum-ers here.

1) Consult a lawyer, showing him the "get ready for consequences letter" and see which lawyer actually do this kind of verbal threat (might come from a phony guy for all we know)

2) Check out the ICANN website provided and actually it should rule in your favor as you started this website before they acquire a similar name domain later on, the WHOIS details should be able to prove it (Prepare this one early)

After everything is done, maybe get your legal representative to send the counter party a letter with all the necessary details so they might cease and desist or should they wish to carry on, at least you know you are not actually committing the offence of copyright infringement.

Just my 2 cents worth and all the best to you!

Vincent

I guess, copy right notices can be only sent if there come one copy the material, not because of domain name as registration is served on first come first serve base/

As they may just be after the domain name then check if the site in question has recently been brought by another company and so they may be trying to aggressively expand their company. If this is the case then you can just hold out, it may be that they go away after a few days. Also if your website doesn't resemble theirs in any way then all your looking at is the name. If it's this then it's a lot weaker. So what you need to do is just make sure that you have not intentionally not infringed on them. If you have had the name for 5+ years I can't really see a problem so just hold out would be the main thing.

Draft a letter back to them stating that they are in violation of your copyright as you have been there since 05

You domain name is in trouble that doesn't mean you are doing something illegal, proceed with the dialogue but just DO NOT let go your domain name for free..

I really wouldn't worry about it too much, maybe spend $100-200 to see what a laywer has to say about it, but unless they really try to sue you in court I wouldn't bother too much, maybe you could see if they want to buy the domain and then not worry about things, I'm sure if you are bothering them that bad they would buy it in a heartbeat.