The phrase "captive audience" means a group of people who are forced to listen or pay attention to something, often because they have no choice or are unable to leave. Full definition
They use those in the army for many statistics since they are as captive an audience as one can get I should think. (drmalcolmkendrick.org)
Also most guys can handle being turned down by a lady in front of her one friend, but most don't want a large captive audience watching as it happens. (beyondblackwhite.com)
It is a witty and direct challenge to the notion of the artist's identity and institutional regulations imposed upon the viewing of art and the behaviour of a supposedly captive audience. (devcas.jynk.net)