It's only dodgy compared to Ponta Delgada or the well groomed areas of London, which are well groomed thanks to immigrant labour. Pickpockets and annoying sodium bicarbonate or basilic 'drug dealers' are quite common in Lisbon, but then evey major tourist destination has pickpockets. The novelty in Lisbon is the fake drug dealers. I don't know about drugs as I haven't seen any needles or addicts or even stoners on the street. Just locals and Brazilians mindng their own business and also lots of tourists from cruise ships.