I was using my phone and for some reason, happened to eject out the SIM card (T-mobile).
I quickly inserted it back and now my phone keeps asking for Privacy Protection Password.
I cannot seem to remember if I set this up in the first place.
Now I cannot use the phone anymore.
Any clue on what I should be doing?
Contact your provider. Your SIM actually comes with data encryption. I did this same thing years ago on a Boost mobile phone. The provider had to give me specific instructions along with a code to unlock the SIM. Either that, or the SIM became corrupted by incorrectly ejecting it. It is not likely that the problem is the phone. SIM cards have their own programming.
Actually this is part of the Mobile anti-theft feature in our phone. @Mahesh - please check if you can remember a password that you might have set while enabling this feature. I’m attaching 3 screenshots for this feature for reference.
Other way is if you can guess who you might have selected as your emergency contact. You can send an SMS from that phone to your locked phone as mentioned in the 3rd screenshot.
Thanks, I will try all the steps you helpful friends mentioned!
The problem is now solved.
I was on hold with T-Mobile in what seems like an eternity. Meanwhile I kept jabbing at the password lists with stops of 30 seconds due to running out of bad passwords and finally got the right one. 
I realized that there are some options to do some texts to a backup phone, but I don’t think they work. They are likely optimized for some asian countries since the text content is all asian words I think.
I got my phone working and thats what mattered most
Thanks all for your help.
Glad that you found the password. We have had few locked out users so far - all of them remembered the password somehow.
For all other users, we will recommend storing the mobile anti-theft password properly or not using this feature at all. The reason is that it is a very complicated process to reset the privacy password if you don’t remember it.
