Legal Question in Intellectual Property in New York

Re: WEBSITE use of site content

You have a copyright in any original work that is fixed in a tangible medium of expression. The law is clear that works on computers and web pages are included. The misappropriation of your art work is a violation of copyright law.

If this is a volunteer project, they would not seem to have any claim that your works were done for hire, that is, as part of your employment. However, the way you describe the circumstances under which the work was created there could be an issue there.

Now for the bad news. You can write and demand they take your works off their web page. You might even write to the provider who hosts the web site and demand that they remove the offending works [provisions of copyright law support this remedy]. As a last resort, you can sue, but that is a long hard road, and you will need to register your works with the US copyright office. They might actually fold, and at least you will be on record regarding your withdrawal from the project.

You did not ask, but you should be cautious about publishing any statements about possible misconduct by others. Anything on the web clearly qualifies as being published for purposes of defamation law. You are entitled to express your opinion, but factual assertions may be characterized as defamatory and you would want to go over that with a lawyer first.