I bought sn back in September from a famous auction website.
Today I had a visit from the police. They said they had had a phone call from police Scotland, (I'm Midlands, England), who were investigating someone selling sn and my details had come up. Basically it was a welfare check and wanted my sn. Fortunately I have 3 tubs hidden in different places , so gave them 1. They threatened to call an ambulance and have me assessed, but I explained I'd bought it in September so they said they would be in touch with mental health services and to expect a call/visit.
So just be wary, I bought it in September!