“Man up” is #4 on the Google Trends list.  Why?

“Man Up” is

• “Man Up!” is a new ABC TV show. 
• Third album by the Danish blues-rock group The Blue Van. It was released on October 27, 2008 in Danish music stores and on iTunes under TVT Records.
• Campaign to stop violence against women
• a phrase that means “brave it, be daring.”
• a phrase that means “to fulfill your responsibilities as a man, despite your insecurities and constant ability to place yourself in embarrassing and un-manly scenarios.”
• a phrase that means “to be strong”
• a phrase that means “To work through impediments and obstacles without whining”

(Phrases taken from the Urban Dictionary)

The ABC TV series is probably the idea people have in mind when searching on it. Official website

Of course the CBS news article points out:

Unfortunately, most critics felt that the show’s tried-yet-true genre of men being boys failed to hit a comedic chord. ABC’s new sitcom "Man Up!" only received a 39 out of 100 on ratings aggregate Metacritic, due to what most critics pointed out as an unfunny, overly used premise.