Oh gosh we covered this 30 pages ago.
Disney Infinity is already tied to your Disney.com account. In order to get a Magic Band and use the features, you have to have...a Disney.com membership. If they wanted to connect the data between the two they don't need to you to scan your bracelet, ROFL. They already have the data. And since people are openly trading bracelets (it just needs to read one to unlock the special feature), it would be incorrect data, even if they captured it.
The only data on that bracelet is a personal identifier code. None of your data is on that bracelet. Letting Disney Infinity know what # is on that bracelet is irrelevant, since both are already tied to your Disney.com account.
Seriously - the people who are worried about this - do you write checks? If you do, you are making an electronic payment anyway - the only difference is you write all your personal data (financial, address, phone often, etc. - and a copy of your signature!) mail it, go through dozens of hands at the post office, to be opened by a minimum wage worker in a clearing house who scans your check and (hopefully!) destroys it. Yet people insist "I don't pay my bills online!" when - yes, you do - you just pay for, and risk your identity and financial info by mailing it to people who make the electronic payment for you.
It's the same thing here...don't be scared of Disney, be scared of the government, law enforcement, etc. going through your every digital tidbit. A Magic Band (which you can choose not to have) is not going to end your world. I think the whole program is stupid - but it's not dangerous, besides the obvious reason that they are risking a lot of resort money on something that in the end no one is going to really care about.