The Kid-Kidnapper

 refers to an unmarked quest in Fallout 3.

Once you have been to Little Lamplight, you have the option to talk to Eulogy Jones about kidnapping one of the children there which in turn nets you this assignment. Convince Bumble in Little Lamplight to follow you to the Child Slaver waiting outside, either by passing a Speech check or by using the Child at Heart perk.

Reward
Eulogy Jones rewards you with the Boogeyman's Hood.

Bugs

 * After Bumble is taken by the Child Slaver outside of Little Lamplight and you've talked to Eulogy Jones and received the Boogeyman's Hood, if you talk to Jones again about luring a kid out of Little Lamplight, she will reappear in Little Lamplight still wearing the Slave Collar. You can lure here outside again, where the Child Slaver will again be waiting. However, the dialogue between the two will not unfold as it should and they will stand there indefinitely.
 * A variation if the above, Bumble returns but the Child Slaver does not. If you convince her to follow you outside again she will follow you everywhere until you fast travel.
 * If you agree to lure a kid out of Little Lamplight, it may cause Eulogy Jones to disappear from Paradise Falls. In the PC version you can recover him by following this guide.
 * Jones has also been known to dissappear with both of his slaves for no reason at all.
 * Note: Sometimes he goes into Cutter's and other buildings, occasionally he and his slaves will get stuck in a space, so search around the whole area first and in the buildings.