Why is it advised to avoid public Wi-Fi for sensitive transactions?

Avoiding public Wi-Fi for sensitive transactions is primarily due to its frequent lack of adequate security measures, which opens the door for data interception. Public Wi-Fi networks can easily be accessed by anyone in the vicinity, and without proper encryption, the data transmitted over these networks can be intercepted by malicious actors. This means that personal information, financial details, and other sensitive data could be captured without the user's knowledge.

When devices connect to these unsecured networks, they are more vulnerable to attacks, such as "man-in-the-middle" attacks, where an attacker can intercept and alter communications between the user and the services they are trying to access. Therefore, it is rarely advisable to perform sensitive activities—like online banking or entering credit card information—over public Wi-Fi due to these security risks.