Pickpockets and other kinds of scams are common-place in Hanoi these days. One of the most prevalent scams in Hanoi is the professional charity collectors. This is what happens; there are two people, the girl dresses up nicely and speak English quite well, and the man rides the motorbike. They always look for single middle aged tourists.
They carry a book with a long list of western tourists and the number of dollars they have donated, of course with signatures. They have cheated so many tourists in Hanoi. Last year, I met an American woman in Siem Riep who told me about a young girl who approached her while she was in Hanoi, using the same story. When I told her that it was a scam, she was horrified.
I've witnessed the scam myself. Yesterday, when I was buying some food for my dog near the Dong Xuan market, I saw a girl speaking with a young male tourist. Finally, she got what she wanted but further drama followed. The tourist gave her some US dollars and there was a $1 note which was a bit old and she refused to take it, asking him to change the note. He didn't have another note and she tried and tried for about 10 mintues but the guy refused to give her a better note. She actually got angry with him, jumped on the back of the motorbike and took off. Today again, when I was having my regular coffee at Cafe Nang in Hang Bac street, I saw a very young, pretty girl doing the same thing to a young guy but after 10 minutes trying he kept refusing. She was very mad, said something in Vietnamese which I couldn't hear then sped away.
Fruit sellers in the old town are another annoying night mare to tourists. There is a group of young women who carry small amounts of pineapples and bananas. They try to put their baskets on the shoulders of tourists, thinking it would be a good photo, then force them to buy their fruit at an exhorbitant price. They often charge $3 for a small bag of pineapple instead of 50 cents. Sometimes, these women shout at the tourists when they don't get their own way. Occasioanlly, other old quarter residents shout at these scammers to leave the tourists alone, some even threatening to call the police.
Everybody needs to work to earn money but these kinds of scams give Hanoi and Vietnam a bad name. The local authority really should do something about it.