Bring your own doggie bag?

I work in a bar/restaurant, and to be honest, for people that know they want to take left overs home, I think it is honorable for them to bring their own reusable containers. It seems to me, the people who are doing this are concerned for our planet and are trying to be more conscious of the of the thousands of places who do not use biodegradable containers. All three of our bars, Flanagan's, Brendan's, and O'shea's use compostable to go boxes and to go cups. We are really trying to "go green" and I admire anyone else who is doing so as well!