Sen. Charles Schumer (D-N.Y.) demanded that the Federal Trade Commission (FTC) require opt-out opportunities before personal data can be collected by companies.

Schumer said it’s a “privacy nightmare” that fitness tracking companies can collect and sell personal data without the consumers’ consent or knowledge.

“Personal fitness bracelets and the data they collect on your health, sleep, and location, should be just that — personal,” Schumer said Sunday. “The fact that private health data — rich enough to identify the user’s gait — is being gathered by applications like FitBit and can then be sold to third-parties without the user’s consent is a true privacy nightmare.”

Users of fitness tracking technology typically enter personal health information such as weight and blood pressure and then are advised on a workout routine. Schumer said there are currently no federal protections to prevent these developers from then selling that data to a third party without the wearer’s consent.

He called on the FTC to require fitness device and app companies to give consumers the ability to opt out before their personal information is sold. Schumer said the data sales could lead to some consumers being discriminated against because of their health.

“If companies of fitness devices have the ability to sell personal health data to insurers, employers and others, users should be alerted and given the opportunity to decline,” Schumer said. “The FTC should require fitness devices and app companies to adopt new privacy measures that will help conceal the identity of individuals and develop policies to protect consumer information in the event of a security breach.”