SIM card readers aren’t that new, however, SIM card readers that can also get the deleted data off of the SIM are. Basically you’ll be able to read deleted texts, numbers, contacts, all sorts of stuff as long as it hasn’t been written over by a new file.
You can also use it for the more legitimate task of backing up and/or editing your own phone’s phonebook and contact list, but that would be a lot of money lost. Recommended questionably legal uses would be on your offspring’s cellular device to see what they are up to.
Recommended uses to avoid are stealing your superior’s mobile device and using what you find to extort a promotion, mainly because its illegal, but also because its just wrong. The reason you won’t be buying it just to edit your contact list is because it costs $149, have fun spying.