LOS ANGELES (Reuters) - California's multi-billion-dollar adult porn industry ground to a virtual halt on Thursday after a popular actor tested positive for the virus that causes AIDS (news - web sites). Industry advocates immediately called for a 60-day moratorium on filming so that others could be tested. Actor Darren James tested positive for HIV (news - web sites) on Wednesday in screening conducted routinely on the industry's 1,200 regular actors by the Adult Industry Medical Healthcare (AIM) Foundation, the foundation's Dr. Elizabeth Mitchell (news) said. They must show negative tests to keep working in the industry, Mitchell said, adding...