The bicep lock aka bicep slicer aka bicep crusher is a great submission and it wasn't always a restricted move in the IBJJ Rules. It was made illegal in recent years in IBJJF competition for all but brown and black belts. The governing body must have determined it to be dangerous, but I honestly feel it gets a bum rap. Back in the day we drilled this sub and sweeps from the guard position from which it is commonly attempted.
Most of you aren't allowed to apply this submission in competition, because of that, it's probably not the sub you want to invest too much time in. However, Comprido Medeiros thinks enough of it to show us a trick was to get this little under-achiever-of-a-submission from side control. I'll add that this position is also quite gettable from omoplata after your opponent has forward rolled to defend (landing in your side control).
Try this out in play, grapplers. But, if you get caught, you didn't learn it from me. Happy bicep crushing.
Special thanks to MMANuts.com for the sweet video goodness.