My Experience...
Last two weeks ago, I met two guys under an Airtel Umbrella Promoting Airtel free simcards registeration. I approached them and requested for two SIM for business afterwards the requested for my NIN which I gave. I subsequently bought 1,000.00. cards from them. On getting home I got a notification that stating that I have register four (4) different numbers. There I remember how a guy approached me year back in one phone shop that there are available registered SIMs if am interested or if I know anyone who could be interested? I asked home whose name will this carry now ? He said just buy and use it. I told him this can be disaster waiting to happen.
We must be careful regarding SIM card issuer especially those hawkers. Since that day I haven't seen them with their merger phone again.
Lastly I visited their main office to complaint in my state here one of the front desk staff requested for the number that aren't mine to disable them ASAP. I wrote out those numbers for her. I believed she did what's expected of her.a