Like other posters have stated the finger scanners are nothing to be wary of. They are not taking your fingerprint. I do understand your concerns. It is not that you have anything to hide it is a matter of the whole "Big Brother" thing. WDW has a file on you anyway

Every time you use your room key, make a complaint or a compliment, make a call....it's all there.
This is OT but just a note for your own protection. I was recently a victim of identity theft. A restaurant in the town where we live and are frequent patrons of was part of a credit card skimming ring. I only know this because I was privy to information others don't have....I saw the arrest report. A woman working in the restaurant was skimming credit card numbers and both of my AmEx cards were compromised. Imagine my surprise when I looked on line at my bill and saw $12,000.00 worth of Vuitton luggage charged to my account from a Saks in Columbus OH on my gold card and $15,000 of jewelery on my Plat. The charges were removed but it is a tremendous hassle in protecting myself from more damage.
The woman at AmEx fraud dep't gave me some tips I would like to pass along to you, since we are all travelers
As what was told to me the most secure way to use any credit card is the less it it is exposed the better. So do charge to your room and do not carry your credit cards around the parks...lock them in your safe. I am not saying this is 100% but it is much, much safer.
When using your card, make sure you get your OWN card back. This is true especially in restaurants. Look at your card before putting it back in your wallet to make sure it was not switched.
Be wary of a "double swipe" if you see your card being swiped in 2 different machines question it immediately. They may make an excuse that 1 machine is not working and they have to use a different one. The skimming device may also be on the person.
When using your card, do not let anyone see it or see your pin #.
I know these things may seem obvious, but then again I never thought this would happen to me. I always thought credit card companies call you when there is an unusual charge. In most cases they do, but criminals know their way around these things. Just a note to everyone to be alert with their cards and protect yourself as much as you can during all times and especially the Holiday shopping season.
If you live on Long Island, Nassau County, PM me and I will tell you the restaurant for your protection. I don't know if I am allowed to post the name and address of the restaurant on a public message board or I would.