U.S. environmental activist Erin Brockovich, made famous by the film bearing her name, has launched a citizen platform tracking data centre projects across the country.

The self-taught legal assistant first made her name helping expose a water contamination scandal in Hinkley, California, in the early 1990s, when energy giant Pacific Gas and Electric Company (PG&E) was found to have poisoned the local water supply.

The resulting class action lawsuit ended in a $333 million settlement for the plaintiffs.

Director Steven Soderbergh brought her story to the screen in "Erin Brockovich," earning Julia Roberts the Oscar for Best Actress in 2001.

Brockovich has since built a career taking on corporations over pollution concerns.

Now 65, she is targeting data centres, the sprawling buildings packed with microchips and servers that power cloud networks and, increasingly, artificial intelligence.

Across the United States, communities and elected officials are moving to regulate, limit or outright block new data centre construction.

"I am watching you, communities showing up and speaking out," Brockovich wrote on the dedicated webpage at brockovichdatacenter.com.

Their concerns range from spiking electricity prices and fossil fuel use to water consumption, noise and waste.

The platform features a real-time map of proposed and under-construction data centres across the US, fed by tips from the public and press reports, with users invited to update the database.

For now, it lists only a few dozen projects; a fraction of the hundreds of centres estimated to be in preparation or under construction nationwide.

The site stops short of calling for a moratorium or ban on the centres, saying it wants to spotlight "the need for sustainable, secure, and efficient AI data center practices."