The real problem is that Everybody is afraid to share data with them because they know Watson will become better at the expense of company's business model.
The issue of data privacy and protection is complex. IBM provides explanations and opt-outs in many of the Watson services.
For example, you can set the X-Watson-Learning-Opt-Out header on speech-to-text calls to prevent retention and use of your data for learning. [1]
[1] https://www.ibm.com/watson/developercloud/doc/speech-to-text...