Among its many disclosures, the special counsel’s 448-page redacted report on Russia’s interference in the 2016 presidential election revealed that the investigation was stifled by the use of ephemeral and encrypted messaging systems.

“Further, the Office learned that some of the individuals we interviewed or whose conduct we investigated—including some associated with the Trump Campaign—deleted relevant communications or communicated during the relevant period using applications that feature encryption or that do not provide for long-term retention of data or communications records,” the report noted. “In such cases, the Office was not able to corroborate witness statements through comparison to contemporaneous communications or fully question witnesses about statements that appeared inconsistent with other known facts.”