I figured I'd throw my hat into the ring as far as solutions go. Like the description says, you must PICK 50 locks.
Now, you can do it "legit" on your own, which can be either really easy or really hard, depending on how good you are at the mini-game (I'm terrible), or you can "force" the lock. But be careful, because this may break the lock, and keep you from getting into it, unless you have the Infilitrator perk. And who wants to wait? You want what's in that safe NOW, right?
I tend to always force them. BUT, if you're taking this route, SAVE FIRST. Let me repeat that, SAVE FIRST. It will save you a LOT of time and frustration. If you break the lock, reload and try again. (actually saving first helps with speech challenges and hacking too, don'tcha know?)
Lock values are as such: 25 for easy, 50 for average, 75 for hard, and 100 for Very Hard. (so plan your skill points accordingly)
Also, there's a terminal and a safe in the Farragut West Metro Station (east of the Super Duper mart, and north of Wilhelm's Wharf, across the river from both of them). You can pick the safe, lock it with the terminal, pick the safe, lock it, pick it, rinse, lather repeat. Boring, but it works.
Well, that's my contribution! Hope it helps!