Here you can see lots of videos with cage and BDSM

Cages are another method that mistresses use to restrain their slaves, and it gives another level of humiliation by equating the slave to an animal by forcing him to sit in a cage.

In these clips you will see a mistress lock her slaves in a cage and force them to sit there for a long time.
Usually this is a prelude to some more fetish stuff, and the slave is taken out of the cage to be a toy for his mistress.