I think that depends on the gliders and the area that they will be in. I would think for one, your gliders would have to be very, very
bonded with you. The area would also need to be gliderproofed from holes they could escape through/areas to get stuck inside, any pesticides, other animals, et. and you would need to watch them very carefully for someone trying to tear through the screen or get into something they shouldn't.
I personally wouldn't risk it but my gliders are chewers and tear through things easily. I have a screened in porch as well and my gliders don't go out there. There are just too many little crevices and small tears in the screen that I would think my gliders could get through. And once out, there would just be no way to control the elements to ensure they wouldn't get hurt or lost.
Maybe someone else on the board lets their gliders out or has used screen for a cage and can help you more. <img src="/ubbthreads/images/graemlins/thumb.gif" alt="" />