Google told U.S. senators the company continues to allow developers to scan for specific keyword targets and then share data from Gmail accounts, according to a letter made public Thursday.

Media reports suggest that the company shared details about its add-on privacy policies for Gmail for its third-party app, but did not fully address questions from U.S. senators about what happens when developers break the rules.

In the letter, made public on Thursday, Google said it relies on automated scans and reports from security researchers to monitor add-ons. The company said users must give their consent before extensions are activated. That consent may include the ability to look for keywords that assist in targeting ads.

Apps can share email data with partners to analyze the behavior of users and improve their ability to target ads to them. “When users sign up to Earny, a tool that compares receipts in inboxes to prices across the web, their inboxes are also scanned by the computers of a different company, Return Path Inc., which collects data for marketers,” the WSJ reports.

In June 2017, Google said it would stop third-party companies from scanning the content in personal emails to target people with advertisements.

“Consumer Gmail content will not be used or scanned for any ads personalization after this change,” Diane Greene, CEO of Google Cloud, wrote in a blog post. “This decision brings Gmail ads in line with how we personalize ads for other Google products. Ads shown are based on users’ settings.”

Lawmakers sent Google a letter in July following a Wall Street Journal report outlining how app developers gain access to content in Gmail accounts.

The WSJ also reports that on Wednesday privacy officials from Google, Apple, Amazon, Twitter, AT&T, and Charter will attend the Commerce Committee hearing.