Can I be held liable if someone injures themselves as a result of trying to duplicate my project ?
Question? Can I be held legally responsible for this injury as I was the one who posted the project in question?

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Further reading for you.
http://www.instructables.com/pages/search/search.jsp?cx=partner-pub-1783560022203827%3Anpr2q7v5m6t&cof=FORID%3A11&ie=ISO-8859-1&q=liability
HOWEVER none of this means anything unless tested in court :-)
PS I am not a lawyer.