Lawmakers in Massachusetts are considering a near-total ban on buying and selling users’ location data obtained from their mobile devices. This will be the first attempt in the country to curb the billion-dollar industry, writes The Wall Street Journal.

This is provided by a bill called the Location Shield Act, which was considered last month. In addition to banning data trading, it also requires a warrant for law enforcement to access geolocation data. Accordingly, in most circumstances, such information can be obtained with the permission of the court.

The bill has the support of a coalition of progressive activists in the state, where Democrats hold overwhelming majorities in both houses of the legislature and control the governorship. The bill was authored by Sen. Cindy Creem, a Democrat.

Geodata is usually collected through mobile apps and other digital services and does not contain information such as name or phone number. But often the data about the movement of the device is enough to establish the identity of its owner. For example, the place where the phone spends its evening and night hours is usually the user’s home address.

The Massachusetts proposal is part of a statewide push to better protect residents’ digital privacy in the absence of a comprehensive national law. Ten states have passed privacy laws in recent years under the control of both Republican and Democratic legislatures. Several bipartisan proposals are pending in Congress but have not yet received support.

No state has gone so far as to completely ban the sale of users’ location data. The most common approach in other states is to require, in particular, digital services to obtain explicit consent from consumers to collect data and to impose certain restrictions on its transfer and sale.