Identity theft is a serious crime in which someone steals another person's personal information and uses it to commit fraud or other crimes. The two crossword solutions for the term identity thief are IMPOSTER (8 letters) and AMNESIA (7 letters). An IMPOSTER is someone who pretends to be someone else, while AMNESIA is a condition in which a person has difficulty remembering things. Identity thieves often use these tactics to gain access to someone else's personal information.