Firstly the number that displays is computer spoofed, been going on for years, one of the TV programs show someone spoofing a call that using a Mainstream banks fraud number. So dont believe what you see in caller display.
I work in a Corporate HQ with 500 lines, after they get me for 2 or 3 times they reconise the voice and ring off. But the first few are fun, have you done this, can you see that best so far 15 mins. Cut them dead by saying do you really think I am that stoopid. Plus the internet is in a sandbox & via VPN.
And we dont use BT or me at home.
nb it might say newbie, Been building PCs since 386SX25 late 80's
My network is VM connection 200mbit VMDG 480 Gigabit routers Netgear Nighthawk R8000 & R7800 2 x cat5e cables to work room, have 3 gigabit switches at key points. Routers give me 3x 2.4 & 5 5.0 GHz WiFi channels - one for each device.