They can cause you a lot of problems. A stolen or hacked SIM card can be used to run up a phone bill, steal personal information, hack online accounts, steal your identity and even commit fraud. A stolen SIM card gives someone complete access to your phone line, which comes with many concerns.
Wireless phone chargers use magnetic induction to charge your phone. Your wireless phone charger has enough magnetic pull to damage credit cards, security badges, key fobs, gift cards, and hotel room keys. In general, you should always use magnets with caution when working near electronics.
No one who appears to be calling from 0000000000 or 1000000000 actually has those numbers assigned to them. Therefore, they are guilty of this spoofing tactic. Spoofing is when someone or something takes on another identity that does not belong to them—and in this way commits identity fraud.