Surveillance product research group IPVM reported that Evolv Express mistakenly identified certain Chromebooks as weapons, sparking concerns about the reliability and effectiveness of the system. 

According to IPVM, the error occured 60 to 70 percent of the time - a finding disputed by Evolv Technology, which went on to accuse IPVM’s coverage of being 'deceptive' and 'dangerous'. 

Despite these disputes, the reported error rate with Chromebooks underscores the need for rigorous testing and validation of such security technologies. 

It also highlights the potential risks associated with relying on AI-based systems for critical security tasks without thorough independent verification.