Simply dirty jokes along with many other puns on similar words that seem harmless at first but turned in quite a different way ... Another popular one that has gotten around is : Hey baby, wanna come to myspace and twitter my yahoo 'til i google all over your facebook? ...
You will need to use your dirty mind to figure out the true meaning to these.

Noun: a friend who is usually only called upon by a friend when a more primary/prominent friend is unavailable.

Taken from the term “second string” in an athletic competition situation. In football, if the star quarterback gets injured during a play, the second string is called off the bench to replace him/her. A “Second String Friend” is essentially benched until needed, if ever.

Synonyms: Plan B, Second Choice, Secondary Friend, Benched Until Needed

An expression if one of your porfiles in one site is threatened to be hacked up fa sho.