A schoolgirl is chloroformed by her friend's brother. Source: nhentai.net

Zakimort, the sexy vigilante, gets clubbed on the head by gangsters and discovered by the police ,who want to lock her up! "Dormi!", I believe, is "sleep!" in Italian. Source: blog

Batman knocks out Duela Dent, daughter of The Joker

Catwoman is knocked out and then wakes up tied up to a stripper pole. The actual knockout or any unconscious shots are not shown.

Julia Pennyworth, the daughter of Alfred, is knocked out by Alfred through a neck chop

A receptionist at Arkham Asylum is knocked out through a dart.

Catwoman is knocked out by some sort of riot squad

Stephanie Brown enters her home but is knocked out with a blow to the head.

Zakimort was a long running Italian Fumetti series, following the adventures of Fedra Garland; by day, a repectable socialite and housewife...and by night a masked vigilante! Here , Fedra gets into her skintight bodysuit and mask to stop a psycho who's been abducting girls, and almost gets caught and unmasked in the p...

Light is knocked out by a blast from behind

Harley Quinn and the Suicide Squad are knocked out and chained to an altar. In the next issue she's knocked out again.

Amanda Waller is knocked out by someone entering her home

Amanda Waller is knocked out by green rain at a funeral by The Joker.

Harley Quinn is knocked out and bound, both twice by The Joker. She is later found and then she passes out.

Harley Quinn is knocked out through some poisonous vines. She is later shown hanging unconscious, upside down, until someone kisses her and she wakes up

Harley Quinn knocks out Amanda Waller and ties her up with tape.

A part of Power Girls unconscious body is on the cover.

Harley Quinn and Amanda Waller are knocked out through a blast by a cyborg

Harley Quinn unconscious on the cover.

In issue 9, Cloak and Dagger got shot and kidnapped. In issue 10 Diamondback, Kitty Pride, Black Widow (Jessica Drew in this case) and also the new Spiderman all get kidnapped by KO darts. They're all loaded into a van and taken to who knows where. If kidnapping superheroines was this easy, it should be done more...