I lived in London and [A nice part] but still warned my friend when she was visiting about pick pockets.
She was on the train at Earl's Court, and felt a jostle {I'd warned her about this, as this was how I was pick pocketed, jostled by two men on a very empty station {Hammersmith}
She grabbed the jostler, {a child} and said ''MY PURSE!!... astonishingly a woman called back ''Your dropped your purse, Lady'' and handed it back to her, and friend let go of the child. Seems the child was sent out to steal, and the purse would be handed back to those behind her.
I actually watched a woman being ''pick pocketed'' on the Tube..It was crowded, a man was leaning heavily onto her whenver the train swing round a bend.
I thought he was being sexually provocative with her, and I glared at him...he glared back.
When he got off the train, the poor woman said ''I've been robbed''...her tickets, passport , money had gone.
He'd had his hand down her bags which were on her knee, hidden by his ''jacket''.
Padlock any cases, and wear a money belt.
Don't look too 'flash'- no fancy jewellery or watches.