Its the act of copying that troubles me, not the sitting on the source. Old games from companies that have disappeared into the ether is one thing, dumping code from an active company is another.
Does Mame have any policies in place with regards to ethics, and if so what are those ethics in relation to capturing modern arcade machines and their software?
Are these operating companies contacted, with a formal request to preserve their code for documentation and archiving purposes before dumping?