The phrase “I hired Donald Trump to fire people like Yovanovitch" trended on Twitter on Friday morning as Marie Yovanovitch, former US ambassador to Ukraine, testified in front of the impeachment inquiry held by the House Intelligence Committee. And while it may have seemed like a spontaneous outcry from the president's supporters, the phrase has spread at a rate consistent with the coordinated inauthentic behavior expected from a network of bots or sock puppet accounts.

To be sure, many human users are sharing the phrase, including Donald Trump Jr., who tweeted a version of the phrase an hour after the first tweet surfaced: “America hired @realDonaldTrump to fire people like the first three witnesses we’ve seen. Career government bureaucrats and nothing more.”

The way the phrase has spread does not appear to be completely authentic. At least 7,320 tweets (including retweets) were posted that included the words posted in the first 45 minutes, according to an analysis conducted by BuzzFeed News. Within that time period, 83 accounts tweeted or retweeted the phrase over 10 times each.

A representative for Twitter said the company was looking into whether the activity was coordinated. Later in the day, several accounts in BuzzFeed News’ data set were suspended. Twitter subsequently told BuzzFeed News that its initial investigations had not found evidence of bot activity amplifying the phrase.

As the phrase became popular on Twitter, it spread beyond the platform, appearing on YouTube and in two 4chan posts. It is also beginning to appear in public Facebook posts.

Separating bot activity from genuine virality — particularly among pro-Trump social media users, who often operate in ways that look like bots — is difficult. Benchmarks vary, but, according to the Oxford Internet Institute’s Computational Propaganda team and the Atlantic Council’s Digital Forensic Research Lab, tweeting 50–72 times a day is suspicious, and tweeting more than 144 times a day is very suspicious. The rate of posts from many accounts amplifying the anti-Yovanovitch phrase is consistent with automated services.