Top Senate Intelligence Committee Democrat Mark Warner said Thursday he had “some concern” that Twitter had more than doubled the number of users it's notified about being exposed to the Russian election meddling campaign in 2016.

The other coast: Twitter said Wednesday that it notified 1.4 million people via email that they'd been exposed to Russian-linked election-related tweets. It had initially notified 677,775 people that they'd engaged with such content.

“I appreciate that Twitter continues to take steps to address this problem. I have some concern that these numbers continue to grow, but I think it is critical that Twitter — and the other social media platforms — be completely up front with their users about the extent of this attack.”

— Sen. Mark Warner

Why it matters: Warner has hammered Twitter before on its response to the Russia investigation. But Twitter is not alone is increasing the number of users it says were exposed. Late last year, Facebook dramatically increased the number of people it publicly acknowledged had been exposed to Russian accounts and content.