Ever since I was a white belt, I've had a fetish for peoples knees and ankles. As much as I love them, I haven't allowed that to control my overall game by constantly search for a foot or leg. But, if one should appear close to my arm, I can assure you I will most likely take it. Now, as far as submission grappling and BJJ have progressed over the past 20+ years, I still feel there is a lack of "experimentation" with leg attacks.
Wait. I may have spoke to soon. Leave it to those crazy Russians to develop some even crazier looking footlocks than usual. Check out this gnarly toe hold from open guard that you most likely will never catch in live training. But, we can all hope, can't we?