Policymakers are taking action to protect their citizens and democratic systems from online misinformation. However, media consumers usually have a hard time differentiating misinformation from authentic information. There are two explanations for this difficulty, namely lazy reasoning and motivated reasoning. While lazy reasoning suggests that people may feel reluctant to conduct critical reasoning when consuming online information, the motivated reasoning theory points out that individuals are also thinking in alignment with their identities and established viewpoints. A proposed approach to address this issue is adding fact-checking flags in the hope that flags could alert people to information falsehoods and stimulate critical thinking. This study examines the impact of fact-checking flags on media consumers' identification of fake news. Conducting an experiment (n = 717) on Amazon Mechanical Turk, the study finds that experimental participants with different political backgrounds depend heavily on flag-checking results provided by flags. Flags are powerful to influence people's judgments in a way that participants have blind beliefs in flags even if the flag assessments are inaccurate. Furthermore, the study's results indicate that flag assessments made by professional fact-checkers or crowdsourcing are equally influential in shaping participants' identification. These observations provide public and private leaders with suggestions that fact-checking flags can significantly affect media consumers' identification of fake news. However, flags appear to have little ability to promote critical thinking in this experiment.