Mueller says use of encrypted messaging stalled some lines of inquiry

A single paragraph in the Mueller report out Thursday offers an interesting look into how the Special Counsel's investigation came head-to-head with associates of President Trump who used encrypted and ephemeral messaging to hide their activities. 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. 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.