I believe there is a restriction against going to public gatherings during Sfeira (like movies or plays). Does this apply to the nine days? Chabad doesn't seem to think so (http://www.chabad.org/library/article_cdo/aid/144573/jewish/The-Three-Weeks.htm
http://www.chabad.org/library/article_cdo/aid/144574/jewish/The-Nine-Days.htm) but I find it hard to believe. Did they leave it out, or is there really no restriction?