"The KGB Lawsuits" (1995) by Brian Crozier

[In Western countries, the Soviet KGB fostered] lawsuits, with the aim of immobilizing opponents and, in due course, ruining their reputations.---Brian Crozier, The KGB Lawsuits

Brian Crozier's The KGB Lawsuits (1995) describes Soviet-era "active measures." The back-cover of the book observes:

Active measures included disinformation (the deliberate spreading of false information), either to propagate opinions favourable to Soviet policies or to discredit hostile views and those expressing them. Forgeries played an important role, and so did the fostering of lawsuits, with the aim of immobilizing opponents and, in due course, ruining their reputations [my emphasis]. Those included in such activities in the West were not necessarily aware that they were being used. Such people were known in the intelligence world as "unconscious" or "unwitting" agents.