Your phone is encrypted

[zpwls]

I have an HTC 10 with T-Mobile. Several weeks ago I started getting the "Your phone is encrypted" screen when restarting, prompting me to enter my pattern. I'm pretty sure I never opted in to having my data encrypted. Is it possible that it could happen automatically without the user's permission?

 

[N4Newbie]

Have you added a corporate email account to your phone recently? If so, you may have unwittingly agreed to turn on encryption - as well as some other potentially nasty rules. For example, https://technet.microsoft.com/en-us/library/aa998614(v=exchg.150).aspx

Another possibility is that a recent OS update may have slipped encryption in when you weren't paying attention.

 

[zpwls]

Have you added a corporate email account to your phone recently? ... Another possibility is that a recent OS update may have slipped encryption in when you weren't paying attention.

No corporate email. I suspected a system update but didn't think they would force encryption.