A Personal Boundary prevents anyone from invading your avatar’s personal space. If someone tries to enter your Personal Boundary, the system will halt their forward movement as they reach the boundary. You won’t feel it – there is no haptic feedback. This builds upon our existing hand harassment measures that were already in place, where an avatar’s hands would disappear if they encroached upon someone’s personal space.
According to Meta, the Personal Boundary is always on, by default. The reason is because Meta wants to use it to help set behavioral norms in virtual spaces. That said, it is possible for two people to willingly choose to extend their arms outside of their Personal Boundaries in order to do a high-five or a fist bump.
The Verge provided some background that could have been the reason why Meta added the Personal Boundary. According to The Verge, when Horizon Worlds was in beta testing, at least one beta user complained that her avatar had been groped by a stranger. The Personal Bubble gives everyone a two-foot radius of virtual personal space, equating the equivalent of four virtual feet between the avatars.
Personally, I think that Meta is doing the right thing by instituting a Personal Boundary. It shows that they understand that some of the people who want to experience Horizon Worlds or Horizon Venues will choose to behave badly towards others. The Personal Boundary makes it impossible for them attempt to grab, grope, or sexually assault someone in the VR setting.