Implement user switching in the SMC client. The old user logs out and all user specific settings are removed with the respective profiles. Optionally, additional restrictions will apply. If the new user logs in the restrictions will be removed and the personal profiles from the new user will be applied. This makes e.g. an iPad capable to support multiple users in a restricted environment (schools, hospitals, police)
William Redig commented
This can be very useful for shared devices, as described above, specially on the tablets. For phones, I think it will be rarely used.