But the attorneys general said the privacy update "appears to invade consumer privacy."
"Consumers have diverse interests and concerns, and may want the information in their Web History to be kept separate from the information they exchange via Gmail," they wrote.
The attorneys general argued that users of phones powered by Google's Android operating system might have little choice about opting out of the information-sharing.
The attorneys general also expressed concern that consolidating the personal information could make users more vulnerable to hacks.
They said that if the changes really were positive for consumers, Google would offer the service as an "opt-in" feature.
"Unfortunately, Google has not only failed to provide an 'opt-in' option, but has failed to provide meaningful 'opt-out' options as well," they argued.