AUSTIN (KXAN) — Not all ATMs are created equal.

ATMs at banks or financial institutions are highly regulated. But the rest — known as white label ATMs — have no oversight, are often purchased over the internet and can be used for financial crimes or human trafficking.

State Rep. Senfronia Thompson, a Houston Democrat, filed legislation to establish a registry for white label ATMs in an attempt to cut off the cash flow for human trafficking operations.

House Bill 2629 is currently waiting to be scheduled for a vote by the Texas House with a little more than a month remaining in the legislative session. With time running out, advocates of the legislation believe the delay is being caused by opposition from the ATM industry.

“(White label ATMs) are able to pull in $100 million a year,” Thompson told KXAN. “Anytime is a good time to stop the slavery of women and men into a web of crime like human trafficking.”

The legislation is closely tied to violence at three Atlanta spa businesses last month that left eight people dead. The locations had, among other things, white label ATMs and reviews on exotic websites in common.

According to the nonprofit Children At Risk, there are 900 suspected illicit massage businesses in Texas. There were more than 52,000 unique ads for escort services in Austin last year, according to a report from the organization.

Detective Joseph Scaramucci, who investigates human trafficking for the McLennan County Sheriff’s Office, said a registry of ATMs would help law enforcement track sex crimes to the source of the money. Most illegal sex customers deal in cash to avoid getting caught, he said.

“If we can prevent someone from being trafficked then we’ve won,” Scaramucci said. “If we can do everything that we can to regulate those ATMs, and we have the ability to then follow the money, that’s going to open tons of doors.”

Andrea Zarate, an advocate with the survivor-support organization SAFE Alliance, said tracking money in human trafficking cases can only be one tool, though.

They said human trafficking and sex crimes often prey on an individual’s basic needs — like food or shelter — with no money being exchanged.