Given the gap between the date of the data (between 2017 and 2014, depending on how bad you think LJ were at not deleting data for old accounts), my guess is that it was used to target specific Russian accounts until it was sold to people do did mass spamming with it.
no subject
https://twitter.com/troyhunt/status/1050391317266620416
The admin here were also told back then.
Given the gap between the date of the data (between 2017 and 2014, depending on how bad you think LJ were at not deleting data for old accounts), my guess is that it was used to target specific Russian accounts until it was sold to people do did mass spamming with it.