Shadow Markets is the seventh episode of the sixth season. It was released on 6 November 2009.
The team finds themselves protecting a hacker who has exposed their own sting operation when he's targeted by assassins.
The title is an allusion to the Dark web, black markets and all manner of 'off the grid' transactions.
Michael Harney and Pablo Schreiber appear together in this episode and co-star in Orange is the new black.
The hacker pseudo-language "leet", which substitutes numerals and non-alphabetic characters for normal letters, features strongly in this episode. The series title, "Numb3rs", is leeted.
In the beginning of the episode, when Amita is giving her presentation to the computing conference, the footage of the online battle behind her is taken from Season 4, Episode 7 where she plays the MMORPG Primacy.
In a close-up shot, Charlie draws a circle on a map with a fat marker. In the next shot and subsequent close-ups, the first circle is drawn with thinner markers, as are the other circles he draws.
[This appears on the beginning of the episode] 50 million dollars 6000 customers 4 illegal markets $11.29 stealing one person's identity