I don’t understand how could someone turn off my find my iphone without my password

First: You did the absolutely right thing marking it as “lost.”

Turning off FindMy requires BOTH your phone’s passcode AND your AppleID password.

Unless the thief had both of those, it’s doubtful he turned off FindMe.

If FindMy” had indeed been turned off you wouldn’t see the phone in FindMy.

Have you reported the theft to the police AND to your carrier?

Don’t be in too big a rush to erase your phone; doing so WILL prevent any further location-finding.

See more guidance here:

https://support.apple.com/en-gb/HT201472

All they had to do was restore it with a Windows or MacOS computer. Restoring a device erases it and thus breaks the tracking link between the device and Apple’s icloud Find My system.

As long as the device is still listed under your AppleID (https://appleid.apple.com/) as a trusted device, then activation lock remains in effect and prevents anyone from activating and using the erased device.

Find My was introduced as a user feature to find missing devices, not to track stolen devices. Find My is tied to your devices and your iCloud account so you can track them remotely. Activation Lock, tied to your AppleID, not iCloud, is Apple’s anti-theft system to prevent thieves from activating and using stolen or found devices.

Two different systems - one, yes, can be easily disabled by erasing device with a restore. The other though can only be defeated by knowing the AppleID password and, if using 2FA, having access to someone’s trusted devices or trusted phone numbers.

Find My was introduced as a user feature to find missing devices, not to track stolen devices. Find My is tied to your devices and your iCloud account so you can track them remotely. Activation Lock, tied to your AppleID, not iCloud, is Apple’s anti-theft system to prevent thieves from activating and using stolen or found devices.

Two different systems - one, yes, can be easily disabled by erasing device with a restore. The other though can only be defeated by knowing the AppleID password and, if using 2FA, having access to someone’s trusted devices or trusted phone numbers.

Note that disabling activation lock requires removing the device from your AppleID (I.e. as a trusted device at https://appleid.apple.com/) while disabling Find My requires removing the device from iCloud (https://www.icloud.com/find) or erasing it with a restore as new with a Windows or MacOS computer. Two different things. They’ve been separate required actions for a long time now.

Best written consolidation of the “three-tiered protection scheme” I’ve seen.

Thank you !

Re: “… Two different things …”

I think some confusion might stem from the fact that it is the activation of “Find my iPhone” on the device which “arms” the Activation Lock.

I suspect that this leaves a impression of “entanglement” of the two systems more than they truly are.

Thanks.

Do you have a backup you can restore on another device to get your Thesis back?