There are two things. One is, for a general national contact-tracing app, we've already heard about the challenges with making that mandatory. There are serious civil liberty issues with forcing people to carry their cellphones everywhere and have them running these apps in the background.
The new wave that I alluded to in my comments, and it's coming very fast, is going to be mandatory contact-tracing apps in workplaces. People will be going back to workplaces where the employer says, “You must use this contact-tracing app if you want to be part of this workplace.” That may be necessary to prevent major outbreaks of disease or control them within workplaces, and we've certainly seen this as an issue, but those apps are likely to be mandatory.
In addition to these debates about the national contact-tracing app, we need to start thinking about what the boundaries and parameters should be for these mandatory workplace apps that are coming.