said by ATTCustomer :May not be illegal, but probably violates your terms of service with AT&T.
If they find out, they may cut you off.
In most states there are statutes on the books for "theft of service" which would include hooking to your neighbors utilities and services.
There are also other laws like tampering with a meter, usually for electric or water, and tampering with a utility companies equipment, for example AT&T is considered a utility and everything from the street to the dmarc on your house is their property.
