We don't have chickens yet just ducks. Our enclosure will have a secure roof and have fence dug under about a foot down and out. Will we still have to lock them in their house at night?
If your run is secure, than theoretically, no. I lock my chickens up in their coop and my ducks stay in the run at night simply because the ducks torment and bother my hens...so I want my chickens to get some "quiet time" and not worry about being bothered by my big, dumb ducks.
If your run has 1/2" hardware cloth as does your coop, then your run is as secure as the coop. But if your run has "chicken wire" of the 1" or 2" type, it is not nearly as secure and they'd be better of locked up in the coop.
I would lock them up if I were you. You may not have trouble with predators, but if you do, you'll wish you had locked them up. I don't know what animals live in your area, but to be cautious, you may want to lock them up.
I agree with pdirt, if your run is hardware cloth secured then you are good to go. If you are the worry type then lock them up for double security, I don't though.
I would say it depends on predators in your area and what your run is made of. A determined dog can get through hardware cloth. It will however deter most less determined animals. I live in an urban area and my run is made of 2x4 welded wire fencing. I added chicken wire around the lower portion to keep the chickens from sticking their heads out, not to keep anything from getting in. Learned that one the hard way. I'm going to blame the dog as she should have kept other animals out of the yard. She has lived in the yard outside the run for 2 years before I lost one chicken. I never locked mine in the coop in a secure run.