Madonna finally joined one of following social networks in February 2013. Which network was it?

Explanation

Madonna Louise Veronica Ciccone was born in Bay City, Michigan, USA 16 August 1958. She has been married to Sean Penn (1985-1989) and Guy Ritchie (2000-2008). Ritchie is the father of her son Rocco, born in 2000. She has a daughter, Lourdes born in 1996, with Carlos Leon. Madonna also has two adopted children from Malawi, David Banda (born 2005) and Mercy James (born 2006).