Twitter and Facebook have hidden the evidence of Russia's efforts to sway American public opinion. Over the course of the 2016 election, Russia's Internet Research Agency (IRA) published controversial content on both platforms to spread misinformation and spark division in the United States. But there is little evidence of the IRA's efforts left on Twitter and Facebook today.

Twitter considered the IRA-linked accounts to be in violation of its terms of service and suspended the accounts, causing the accounts' tweets, follows, and followers to be removed from public view. Facebook acted similarly, removing the IRA pages from its site. This has made it nearly impossible for journalists and the public to independently investigate the actions and impact of the Russian controlled accounts.

Twitter and Facebook wiped their platforms of the IRA—and in doing so, took a dangerous step away from transparency and public accountability.

I run PolitiTweet, a site that monitors and archives the tweets of prominent politicians and other public figures. When Twitter began to suspend the accounts linked to the IRA, I noticed that a surprising number of prominent public figures—including Eric Trump, Sean Spicer, and Kellyanne Conway—appeared to be deleting many of their retweets.

But it was Twitter, not the figures themselves, who deleted the retweets. It turns out that the figures had retweeted content from IRA accounts, causing their retweets to also disappear from public view when Twitter suspended the IRA accounts.

Twitter not only removed the IRA accounts' tweets from public view, but also removed all records of interactions between IRA accounts and prominent public figures. Retweets of IRA accounts by the figures were only noticed because I happened to be independently monitoring the figures myself.

Twitter's approach to handling the IRA accounts has been deeply troubling. While suspending the IRA accounts effectively halted the IRA's Twitter campaign—suspended accounts can't tweet, after all—it also sheltered the IRA accounts from public scrutiny.

Facebook's approach to halting the IRA's campaign has been no less objectionable. Like Twitter, Facebook completely removed the IRA's pages from its platform, and in doing so removed all public record of the pages' content.

Now, there is no public record of the IRA accounts on Twitter or Facebook. Twitter sent out warnings to accounts that interacted with IRA trolls, but little other trace exists. If you try to load the profile page of an IRA account now, you'll see a message that says the account is suspended or removed. You won't be able to see who followed the account or what the account posted.

It's now nearly impossible for the public to investigate how the IRA content spread and who shared it. For example, we only know that Donald Trump Jr. retweeted the IRA Twitter account @TEN_GOP because PolitiTweet happened to archive it.

Complete removal of the IRA accounts is not the platforms' only option.

I propose an alternative new policy for Twitter and Facebook to deal with IRA accounts: freezing. Frozen accounts wouldn't be allowed to make new posts, and their content wouldn't show up on users' feeds or in search results. Anyone who visits the profile of a frozen account would be greeted with a warning that explains why the account is frozen, but they would still be allowed to view the account's history. The account would still be available for public scrutiny.

Instead of suspending and removing entire IRA accounts from its platform, Twitter and Facebook should have frozen the accounts. Misinformation would cease, but transparency would remain.

I admit that freezing is not a one-size-fits-all policy. There are situations in which complete removal is a better approach. For example, accounts or pages that share illegal content (such as child pornography) or information that threatens the personal safety of others (like home addresses) should be taken out of public view. But IRA accounts share neither.

Fortunately, it's not too late. The social media companies haven't deleted the accounts, they've simply suspended them—the IRA accounts still exist in their databases. Twitter and Facebook can still adopt this alternative suspension policy.

Until then, however, sites like PolitiTweet are the only record of the IRA's misinformation campaign—and PolitiTweet only archived a small subset of the IRA's efforts. If Twitter and Facebook want to restore public trust in their platforms, they must emphasize transparency. So far, they have done the opposite.