> "We encourage people to actively log in and use Instagram once they create an account. To keep your account active, be sure to log in and share photos, as well as like and comment on photos. Accounts may be permanently removed due to prolonged inactivity, so please use your account once you sign up!"
Source: https://www.facebook.com/help/instagram/294919817276863
The wording is terribly obtuse and seems targeted more for username squatters.
Would be helpful if Instagram defined what a period of prolonged inactivity is. Shady nonetheless, considering they didn't even notify her informing her that her username was revoked due to inactivity.