When playing Call of Duty: Ghosts online, it is highly recommended that you play in Public Matches, or that you only play with players you know and trust when playing in Private Matches. Accepting Private Match invitations from players you do not know and trust may place you in a hacked lobby, which can leave you vulnerable to having your stats artificially padded, or boosted.
Please note that having your stats knowingly or unknowingly boosted by a hacker may lead to your stats being damaged beyond restoration, and may also be grounds for a ban.