A step-by-step checklist to lock down your phone against theft and loss, and to browse more safely. Tick what you've already done — we don't send anything anywhere, only you see your answers.
Act in this order: 1) Mark it as lost at android.com/find or icloud.com/find (depending on your phone) to lock it remotely. 2) Report the theft or loss to the police with the IMEI you saved. 3) Tell your carrier to block the line. 4) Change the passwords of any accounts that were open on the phone, starting with your email.