You send more 'confidential information' than that every year when you file a tax return.

When you buy on line your credit card and you as well as its purchase history is shared among many online merchants -- there are databases for just that purpose. For that matter, there are databases that dating sites and social media sites use to investigate and validate users. That's right, when you register for many of these websites your browser is fingerprinted, your IP (block) checked against that browser fingerprint, other information that the browser gives up is scrutinized and shared in the database.

All Insurance companies require your social security number ( and run a credit report) as part of the policy underwriting process.

The one point is; why the preqalification is even necessary? On that I agree, prior to purchase it is not necessary.

It's an overzealous "squeeze-page mentality" a delusion of the "Obamacare folks". A simple registration pre-purchase of a name and email address would suffice.

Even if they wanted to restrict the payment of this insurance's federal subsidies to taxpayer-citizens, I can't see why any pricing information would harm any party -- the more transparency in this process, the insurance offering and underwriting the better.