I have used Emerald almost exclusively for months now. I suggest your friend keep this link and give it to people who insist Emerald is used in content theft or is in any other way a violation of TOS:
http://modularsystems.sl/index.php?option=com_content&view=article&id=3&Itemid=8
One has to remember that Emerald is open source (Like LL's Snow Globe) so individuals can and have changed and added code for their own purposes, sometimes not so pleasant or legal. That is the downside of open source.
The upside is many features that LL might or might not ever get to in a few years and support on both a website and in-world group that leaves LL in the dust.
As far as content theft, Emerald as provided is no more a threat than the program Second Inventory sold on Xstreet. Anything saved to disk must be either your creation or full permission and the results on full permission items is not consistant. I use this feature sometimes to transport builds from OS Grid to SL and visa versa. Trust me, it is a far from perfect system and useless for content theft.
Let the anti-Emerald crusader AR us all. EMERALD IS LEGAL!