Amy Klobuchar, a Democrat, represents Minnesota in the U.S. Senate.

During the summer of 2016, Melvin Redick was — like many of us — posting his thoughts about the election on Facebook. Melvin's profile painted a picture of an all-American family man from Harrisburg, Pa. He was a dad who liked baseball and cared about his country.

But Melvin was hiding something: He wasn't a real person. He was a fake account created to influence the U.S. electorate. We have since learned that there were thousands of Melvins, controlled by the Russians, posting on social media during the 2016 presidential election. And they weren't just creating fake accounts to spread misinformation. They were also buying political advertisements designed to influence American voters.

It is illegal for foreign entities to buy political ads in the United States. But that didn't stop the purchase of thousands of political ads on Facebook, paid for — in rubles — by foreigners.

The reason is simple and scary: Our campaign finance laws have left open an enormous loophole for foreign actors to secretly violate our campaign finance laws and possibly influence our elections. It's time we update the laws so that online platforms are held to the same transparency standards as other companies that sell political advertisements.

More than a decade ago, Congress passed the Bipartisan Campaign Reform Act to regulate political advertisements. It's the law that requires politicians to say, "I approve this message." It also requires groups that run ads supporting or opposing a specific issue to disclose who paid for them, and it requires broadcasters to keep a file — available to the public — of the political advertisements they sell.

The Supreme Court, time and again, has upheld these disclosure requirements because voters have a right to know who is giving them political information during an election. But as technology has changed, we have failed to keep up with this standard because Internet and digital ads are often exempt from the transparency standards established by law.

Political ads on the Internet are more popular now than ever. In 2016, more than $1.4 billion was spent on digital advertisements, nearly eight times more than the amount spent in 2012. But there is little transparency and accountability when it comes to disclosing information about these ads. And without transparency, there is no ability to know if foreign governments are purchasing the ads. This leaves our election system vulnerable to foreign influence.

Election security is national security, and we have to start acting like it. Russian robots have shown us that we need to hold online platforms such as Facebook, Google and Twitter to the same transparency requirements as traditional broadcasters, radio and satellite providers. That's why I am introducing legislation with Sen. Mark R. Warner (D-Va.) that would require major online platforms to keep a public file of the political ads they sell and to ensure that ads are not illegally purchased by foreign nationals. While voluntary efforts are always welcome, we need to put this in law so it applies to all.

In the 21st century, our adversaries will continue to use cyberattacks against us. We need to be prepared to defend our networks against this growing threat to our democracy, especially the most fundamental part of our political system: our elections.

We have only a year until the 2018 elections. Congress must act now — not after the next breach and not after the next "Melvin Redick" strikes. The American people and our democracy deserve nothing less.