Not surprisingly, Facebook wants to avoid claims that it's snooping on users without their full consent. You have to be at least 18 years old to use Viewpoints, and you'll be told what information is collected and how it's used. The company also vows not to sell data to third parties or publicly share your activity without permission.

Viewpoints is only available to Facebook account holders in the US at present. It's planning to offer more registration options and expand to other countries in 2020, however. The company is clearly confident that Viewpoints will get a warm-enough reception. To some degree, it needs people to welcome the app with open arms -- if it's going to get meaningful feedback, it needs as much input as possible.