Google sometimes flags websites with warnings such as “This site may be hacked” or “This site may harm your computer,” which can deter potential visitors. Such flags indicate that a site has been involved in serving malware or spam ads, possibly due to hacking. The guide advises affected website owners to use Google's Search Console for more information and to contact their hosting provider for assistance. It recommends taking the site offline, scanning for malware, and changing all passwords to prevent further unauthorized access. Notifying users about the breach is crucial, and hiring technical help for cleanup is suggested. After resolving the security issues, site owners should scan for vulnerabilities using services like Detectify, ensure regular backups, and request a site review from Google to remove the flag. For further questions, support from services like Detectify is available.