Polite, professional and conversant lady called me...

Polite, professional and conversant lady called me about a MOM foreign labour employment survey. Started by stating that it was to be an anonymous survey contracted to Blackbox by MOM. So I said Ok. Spend about 10 to 15 mins answering many questions. But at the end she asked for my name and address, saying it won't be shared, she also say it is ok if I don't feel comfortable disclosing my address. Perhaps Blackbox is collecting a database for their own use.