In March 2011, Russian intelligence agency FSB notified the FBI with concerns about Tamerlan Tsarnaev and the Tsarnaev family, which had emigrated to Massachusetts nearly ten years earlier. In the letter, FSB included contact information, with addresses and phone numbers, for many of the members of the Tsarnaev family, including Tamerlan and his mother, and warned that Tamerlan was gaining a reputation for associating with violent Islamists.
Cunning Russians. They knew that deliberately misspelling the name would completely disable US security agencies and personnel, thus guaranteeing a successful terrorist attack on the US. This definitely proves Putin and the Russians as bad as Obama says they are.