Final Answer:
A major disadvantage of relying on Web-based e-service is the potential vulnerability to security breaches and data privacy concerns.
Step-by-step explanation:
While Web-based e-services offer convenience and accessibility, a significant drawback lies in the heightened risk of security breaches. The transmission of sensitive information over the internet poses a potential threat, making users susceptible to hacking and unauthorized access. Instances of data breaches can result in severe consequences, including identity theft and financial loss. Moreover, privacy concerns emerge as users entrust their personal data to online platforms, raising questions about how securely and ethically these services handle and protect user information. Therefore, the major disadvantage associated with relying on Web-based e-services revolves around the security and privacy risks inherent in the digital landscape.