I once lost my phone (with a SIM card in it). So I went to a store that served my operator, asked to give me a new SIM. They promptly gave me a new SIM and ac

I once lost my phone (with a SIM card in it). So I went to a store that served my operator, asked to give me a new SIM. They promptly gave me a new SIM and activated it on the spot. The only piece of information I gave them was my phone number. No other verification such as name, ID or SSN was required. This is how easy it is to hijack your cell phone number. It's basically trivial and there is absolutely no risk to it.