Home ยป Which of the following is the oldest phone hacking method used by hackers to make free calls? Cyber Security & Cyber Crime MCQs Which of the following is the oldest phone hacking method used by hackers to make free calls? April 21, 2022 19 Views Q. Which of the following is the oldest phone hacking method used by hackers to make free calls? A. Clickjacking B. DMOS C. Cracking D. Phreaking Answer: Phreaking