"Why wouldn't a personal paradise become addictive?" he asked the
audience, but pointed out that he was old enough to remember similar
worries over movies, video games, and the web. Though just about any human
activity can give rise to addictive behavior, Puttnam doesn't see why
virtual worlds would prove to be any more harmful than other forms of
media, but he wants to see more research done in this area.

"Are we absolutely sure that this is the very best we can offer young
people?" he asked. "Do we really want them to think of themselves as not
that much more than consumers?" His alternative was using virtual worlds
to "encourage [kids] to exercise those same values and skills we wish to
see them exercise in the real world."

http://arstechnica.com/news.ars/post/20071025-british-lord-virtual-worlds-should-teach-real-world-values.html