Hello, thanks for joining us on the forums here.  Yes, you are correct.  If your service is hosted in the US (as it would be with Lunarpages) you would also need to look into US law as it pertains to your topic.

The original post is not an easy question to answer. To some extent, the laws where the host is legally located will apply, the laws where the servers are physically located will apply, and your own country's or state's laws will also apply. Some legal jurisdictions may even claim control over data that is just passing through their territory! This includes all aspects of Intellectual Property Law, including copyrights, permissible content (adult, inflammatory speech, etc.), property and model releases, patents and trademarks, etc. Different countries have somewhat different laws, and within a country, laws may vary somewhat by state or other political subdivision. Needless to say, it can be a mess, and case law (particularly internationally) is not well established.

Generally, the Terms of Service of the host (LP) will tell you the sort of things (if any) that are forbidden or regulated by their national and state law. This will not be an exhaustive list, only general statements. If you have a specific question about any aspect of IPL and what applies to you in international trade, unfortunately you will need to consult with an IP lawyer. That's probably not going to be cheap. If you can't afford to do that, all I can suggest is that you try to find out any regulations that apply to USA/California (for the LP aspect of it), and for your local country (Costa Rica, in this case), try to honor them, and hope for the best. There's no telling what will happen in a Third country (example: you're selling Nazi memorabilia on eBay, and France forbids it) -- hopefully the worst that will happen to you is that you are forbidden to do business there.