Reported him in game for boosting 
And reported to Xbox for having an offensive gamertag.
FUBAR stands for F*ed Up Beyond All Recognition.
- Don't create a gamertag, profile content, Avatar action, Avatar content, or in-game content that references controversial religious topics, notorious people, organizations, or sensitive current or historical events that may be considered inappropriate.
- Don't distribute, post, publish, upload, disseminate or discuss defamatory, infringing, obscene, sexual or unlawful materials in any format (images, audio, video, text, etc.). Prohibited materials include, without limitation, child pornography or illegal drugs. “Sound alike” words or phrases or puns that reference these topics are also prohibited.