If you lost an iPhone or iPad and have to immediately stop someone from using or seeing the data you have on your iPhone / iPad, you can use the remote wipe feature (on iCloud) to do that.
For this, you’ll need to have iCloud setup on your iPhone. If you didn’t activate iCloud on your iDevice, you can’t use this method.
God forbid but just in case you lost your iPhone or iPad, and are almost sure of not finding it back again, you can at least make sure the robber does not misuse your iPad or iPhone. Just in case the iPhone or iPad lost gets connected to the internet, you can make sure all the data is locked or wiped clean.Here’s how to perform a remote wipe on iPhone to erase all data:
First, open your browser (on any system or an iOS device) and head over to iCloud.com
Enter your login information
Click on “Find My iPhone” (even if it’s your iPad, it’s this option you want to look for)
A Map-like interface will show up. Tap on the Devices in the upper left corner.
Choose the iPhone / iPad you want to remove data from.
There’d be a blue icon next to the device icon. Click on that.
You’ll be shown options now. You can choose either Remote Lock or Remote Wipe.
If you clicked on Remote Wipe, you will be performing a hard format on the device remotely. This will erase all the data including photos, emails, contacts and everything, from the iDevice and is irreversible.
The Remote Lock makes sure the iPhone or iPad becomes unusable till you unlock it again yourself through the Find My iPhone in iCloud.com (or the app on iOS).
If you are even remotely sure that you can get back your iPhone or iPad, you can choose this Remote Lock option. But if you are not, you must certainly go ahead with the remote wipe.