So you look at Lockdown and you say to yourself - "This would be great in my kill deck", which you would naturally think of given Jinteki is the go-to faction for mind games and constant stabs of net damage, but let's think of this card 'outside' of a kill deck, why would we need this?
One answer: Faust. Faust is the bane of many corp decks, especially with Runners teching high grip sizes to accommodate excessive use, and let's not forget any respectable Anarch typically auto-includes Mimic because Swordsman has been jammed into so many decks, as well as it being their killer of choice.
Faust does not like Lockdown; it takes 3 cards to break, if left unbroken it prevents the Runner drawing back up to continue fueling Faust, it is outside of Net-Ready Yog range, it costs 4 credits with Gordian Blade, 5 credits with ZU.13 Key Master, and the strength to Rez-cost ratio is very favourable.
Next time you're thinking of splashing those swordsmen, swap them out for Lockdown instead. It's the same influence, and preventing a Runner from drawing cards for the rest of their turn will hurt, even if they're not running Faust. Lockdown isn't a solution to killing Faust, but it sure does slow him down.