Having been robbed by two old ladies in Barcelona, I think concerns about it are valid. I'm a savvy traveller too! If you're approached by someone or a pair selling rosemary or a carnation, don't take your wallet out! They will snatch your money from it. I was quick enough to realize I'd been fleeced by the old ladies, and ran after them. They claimed, of the 70 euros lifted from my wallet "It fell.."
If you're mindful and aware of scams, you'll be fine!
JeanBees, I'm a crocheter and you should have no problem fitting a Stuff Sack with a small project in your MCB, but probably not an SCB. (That's what determines which bag I carry for everyday--if I'm bringing a small tatting project, or a larger crocheting project!) Socks, a scarf, or a smallish shawl shouldn't be any problem at all. As you said, don't bring the needles you will cry over losing, and check out the allowances for scissors and cutting implements, and be careful what you bring along. I was able to bring skinny, sharp steel crochet hooks on the plane both ways to the UK with no problem. Scissors and cutting blades are more of an issue.