Lucid has become increasingly popular as a low-cost provider of online survey responses. In this memo, we share our concerns about Lucid’s recent data quality. First, a large and increasing number of survey respondents are failing attention checks. Second, respondents who pass and respondents who fail attention checks are systematically different. Many respondents who fail standard attention checks appear to provide low-quality data. We conclude that researchers should exercise caution when analyzing data recently collected from Lucid unless respondents were subject to stringent attention checks.