In a letter this week, the Electronic Frontier Foundation called on the bill’s sponsor, California State Assembly member Marc Steinorth, to take out language that covers security cameras.

According to the EFF, the problem with tax breaks for home security cameras is twofold. First, police departments across California keep launching programs that invite citizens to add their home cameras to city-wide surveillance networks.

Some of these initiatives, including one in San Diego, have been marked by bungling as integrating the different cameras has proved harder than expected.

But the EFF worries a fleet of home security cameras could contribute to a permanent state of police surveillance—an invasion of privacy that could be especially intrusive given the rise of facial recognition software. (The use of such software is becoming prevalent among law enforcement, including in Baltimore where police have used it alongside surveillance planes.)

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While some homeowners are likely to be untroubled by the privacy implications of the cameras, there is a second threat flagged by the EFF that may concern them: hacking.

In the last year, there has been an explosion in hacking episodes involving the so-called “Internet of things”—everyday devices that are connected to the Internet. Home security cameras have figured prominently in many such attacks, including a high profile incident in November that saw hackers use millions of captured home devices to knock websites offline. As such, the EFF worries that encouraging more people to install security cameras also opens up new cyber-vulnerabilities.

The group is calling for Mr. Steinworth to scrap the portion of the bill covering security cameras, saying it will encourage law makers to reject the bill if he doesn’t. Steinworth’s office did not immediately respond to a request for comment.