The article reports that it is based on "Analysis conducted using open source tools at the University of Michigan known as the OSOME Lab or Truthy."
OSoMe does not offer any service which claims to track "Kremlin trolls". It does, however, have a service which detects "bots." The website for OSoMe's "Botometer" says:
Botometer (formerly BotOrNot) checks the activity of a Twitter account and gives it a score based on how likely the account is to be a bot. Higher scores are more bot-like.
Note the following: [...]
- Botometer often categorizes "organizational accounts", like @BarackObama, as bot accounts.
Such approaches are known to be not free of false positives. Independent users of OSoMe report some glitches:
Algorithms and other automated tools are not useful in the effective identification of bots, and we should not base our conclusions solely on the results they provide. For example, the algorithm we used to detect bots – the “Botometer” developed by the Observatory on Social Media Project at Indiana University – did not take into consideration the linguistic aspect of tweets in Polish because it was trained on content created in English. It also flagged as bots many professional accounts that tweet frequently (news outlets) or are managed by more than one person (official accounts of politicians and political parties). This means that to effectively detect bots we need to dig deeper and examine the content of tweets, which not only requires a lot of time and effort, but also does not guarantee that it will be possible to say with certainty that a given account is a bot or not.
Karolina Iwanska and Anna Obem, "Digital Propaganda or ‘Normal’ Political Polarization?" Transitions Online, May 2018
Since OSoMe does not claim to track "Kremlin trolls" the real basis of the article's claim is currently unclear. The author cites specific Twitter accounts that he claims are Kremlin-run, but he offers no evidence for this, and in the past such claims have been made baselessly.