Some critics feel that the personal data that ClassDojo collects may not be adequately secured and that the technology is being adopted before the full ramifications of what can be done with that data are considered. Critics also worry that behavior databases can lead to unfair treatment of children.
A teacher's ability to mark a student down as being "disrespectful" worries some critics, as it is more subjective and less clearly defined by standards as traditional grades and formal measures of discipline. There are concerns that these records could lead to unfair labeling of children as "problems" in the future. Teachers also do not necessarily need parental permission to use apps like ClassDojo and parents may not be aware that they are being used.
Aside from security of the data recorded, there are also questions about what the company behind ClassDojo does with it. As of February 2015, the company claims it does not sell or lease data and plans to monetize the service by providing more detailed analysis of children's behavior records to parents and schools. The company may select advertisements for display based on the data it has on children, however.
Alfie Kohn, author of “The Myth of the Spoiled Child”, has criticized the app on the basis of using an outdated behavioral conditioning model of discipline.