I've only been jumped once before, quick story about it..
I've never attempted leg locks before, just watched videos on how to and videos of them being used in competitions.
3 guys, one of them kicked me, managed to grab his leg and dive on what I think was in Achilles lock, pulled up as hard as I could (while being kicked on the ground) until he started screaming, let it go and stood back up, dived for the biggest one, was able to take him down with ease, grabbed the same hold again and pulled up as hard as I could, the smallest guy broke my nose while I was doing this, kick to my face.. When I was getting up he jumped on me and punched me a few times in the face, he got up and ran off.. Suppose he got the better of me.. Got up to see the other 2 on the ground, one of them crying their eyes out, he couldn't run away, the other guy just sort of hobbled away.. Left them there and went home, still have a weird nose from that night
Well, from my experience, leg locks paralyse the opponent so they cant attack you when youre finished.. And they're pretty much impossible to escape if you haven't trained..
But then again, the best defense is a quick pair of feet