Former Paris Saint-Germain striker, Ezequiel Lavezzi and his model girlfriend Natalia Borges have been caught up in a sex tape blackmail plot as hackers are threatening to post their intimate videos and photos online.   Buenos Aires daily La Nacion said the alleged blackmailer demanded £4,000 per video or image not to publish.   A source close to Lavezzi and Natalia told the paper: “They began writing to the couple via two Instagram accounts.   “Not just to him, but also …