Most links lead to French-language pages.
You might not have heard of Paul Bismuth, but you certainly know of the famous French politician who used the name as an alias.
Former French President Nicolas Sarkozy , dogged by corruption allegations, communicated with his lawyer Thierry Herzog using a prepaid mobile phone registered under Paul Bismuth. Herzog suspected — correctly — that Sarkozy's personal phone was wiretapped  by prosecutors looking into Sarkozy's campaign financing during the 2007 presidential election.
It was on that “secret” phone that investigators overheard Sarkozy and Herzog allegedly discussing in great detail proceedings of the investigation  into the illegal campaign financing that they both should not have been aware of.
In part because of those phone conversations, Sarkozy was charged with corruption and influence peddling on July 2. He is accused of trying to influence judge Gilbert Azibert into giving him more information  regarding the proceedings of the so-called Bettencourt Affair , which involved illegal payments made to members of government by L'Oréal heiress Liliane Bettencourt. Sarkozy was investigated for his involvement in those payments, but the case was dropped. 
Aside from their communication still being wiretapped, there was another problem with the alias: the real Paul Bismuth wasn't looped into the scheme. When the news broke earlier this year, he sued Sarkozy for identity theft, but the lawsuit was withdrawn after negotiation between Bismuth and Sarkozy's lawyers.
So how exactly did Paul Bismuth, alter ego of Sarkozy, come about? French persecutors were investigating Sarkozy's staff with respect to allegations that the one-term president received  illegal campaign funding in the 2007 presidential race from the late Libyan leader Muammar Gaddafi, a separate legal issue from the Bettencourt Affair. French law prohibits foreign funding of a political campaign.
Sarkozy's lawyer Herzog came up with the plan to register a prepaid phone under Bismuth's name. According to Lepoint.fr, he explained , “I feared, and with reason, that there would be rogue or illegal wiretapping. And I made sure that I could talk to Nicolas Sarkozy without any eavesdropping, something I was clearly justified to do.”
Initially, only two staffers close to Sarkozy were under investigation and their phone were subsequently wiretapped. As the investigation proceeded and more evidence was collected, prosecutors decided to also wiretap Sarkozy and his lawyer Herzog. Herzog himself is now also under investigation .
The real Paul Bismuth, a real estate developer in Israel, is a former classmate of Herzog. They went to the same high school in Paris in the 1970s but lost contact since. Bismuth was not amused  by the identity theft:
Je trouve ça plutôt cavalier, J'ai dit à Herzog que j'étais choqué et étonné par cette pratique, je n'ai pas pris de gants
I found [their action] rather cavalier, I told Herzog that I was shocked and surprised by this practice, I did not mince my words.
Sarozy's lawyers have argued that it is illegal to wiretap an ex-president, especially in the context of attorney-client privilege . Temps réel, a French news blog, explained  that the conversation cannot be used as evidence, but “nothing seems to prevent judges from listening.”
Sarkozy went on the offensive in the media to clear his name by appearing on primetime news to respond to the preliminary charges. Earlier this year, media speculated that he may try to run again for president, and observers’ analyses  are mixed  on what's next for Sarkozy given this new legal development.
What we do know is that whether Sarkozy runs or not, it will not be under the Paul Bismuth's moniker. Sarkozy seems to have enough troubles on his own without bismuth, a rather toxic element  when used inappropriately, thrown into the mix.