When the practice first came to light in May, Google said the data was fragmentary, but last month admitted that in some cases the data collected was quite detailed and included e-mail addresses, passwords and other personal data.
Now the Federal Communications Commission (FCC) has announced it is looking into whether the actions in the latest disclosure violated the Communications Act.
The FCC said it is committed to ensuring that the consumers affected by this breach of privacy receive a full and fair accounting, according to reports.
The FCC probe comes just two weeks after the Federal Trade Commission (FTC) shut down its own investigation after finding Google had taken adequate measures to prevent similar incidents in future.
The report said it was unclear what course of action the FCC will take if Google is found to have violated federal laws.
This story was first published by Computer Weekly