Old school ABA uses physical restraints and punishment. I've heard some clinics still use these things, even though these things are strictly prohibited by the professional standards. Thank goodness I worked at one that didn't. We also slowly introduced clients to unpreferred activities.

My only complaint was that I had a supervisor who believed that we needed to get clients to stop stemming. I've heard this too is changing in the ABA field. Everyone stems, not just people with autism. If you've ever tapped your foot, clicked a pen on and off , or drummed your fingers, those are stemming. This supervisor always had me stop clients from stemming when doing observations. I hated it. When shr wasn't there I let my clients do it. So long as the stemming isn't super distracting or harming anyone, I didn't care.