Green’s Dictionary of Slang

(US Und.) any crowded area, e.g. a theatre exit, which offers opportunities to a pickpocket.

1914

Jackson & Hellyer Vocab. Criminal Sl. 19: breaks [...] Any place of exit where throngs of people pour through en stream, as from a theatre, from a convention or other popular gathering, or from a street or railroad car or from a boat, all of which afford facilities for the pickpocket to operate [...] Example: ‘The guns are rooting into the swell mob at the Grand Opera breaks.’.