Anyone who’s seen the Julia Roberts blockbuster “Erin Brockovich,” which is based on a real story, knows that it isn’t smart to mess with the feisty legal worker. Even so, Erin’s real-life ex-husband, Shawn William Brown, and ex-boyfriend, Jorg Lawrence Halaby, have been charged with trying to extort more than $300,000 from Erin and her boss, attorney Ed Masry. (Albert Finney plays Masry in the movie.) “The threat was that they were going to go to the press and say that Erin and I had a sexual relationship and that Erin was a bad mother,” Masry told the Los Angeles Times. Hidden cameras caught the alleged blackmailers and their lawyer accepting checks from Brockovich and Masry in exchange for silence from the three men, who were arrested on the spot. Said the sharp-tongued Brockovich to the Daily News of L.A.: “Frankly, this whole thing really makes me sick.”