Rocco Ritchie, son of singer Madonna and filmmaker Guy Ritchie, has been arrested for possessing cannabis.The 16-year-old was allegedly caught with the drug in his rucksack in Primrose Hill, north London, after neighbours called police when they spotted him "smoking or doing drugs" in the area, reports dailymail.co.uk."Rocco has become a well-known figure in the neighbourhood and not for the right reasons. Hes been repeatedly seen acting suspiciously," a source told The Sun newspaper.-WTN