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 7 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