No. Passively listening only requires dumping whatever flies over the interface of some router. Done! Very hard to detect. You can also just scan for keywords a

No. Passively listening only requires dumping whatever flies over the interface of some router. Done! Very hard to detect. You can also just scan for keywords and only start dumping traffic when triggered. With SSL, you cannot retroactively decide that you'd want to dump traffic. You have to MITM from the beginning. That's point 1. Point 2: Detection. Actively MITM-ing an SSL connection requires you to (if the CA Chain-O'-Trust works as supposed) give away the fact that you own a (valuable!) compromised CA authoritative cert. You would want to use such a cert for a targeted attack, not waste it on blanket surveillance and get found out (and called out) within a couple of days. If you don't own a root cert but rely on vulnerable implementations, or implementations such as this one which do not rely on the CA infra, same story. You do not want to waste that on blanket surveillance and get caught. You'd save it for the /special occasions/. SSL-MITMing everyone, all the time, as in blanket surveillance, is unfeasable even without CA chains. You'll get called out on it by people that do check cert fingerprints once in a while. This is a different kind of scalability than the computational order-of-complexity one that you seem to be thinking about.