Romania during the Ceaucescu era (c1988). I was taken in by some students and stayed with them for a few nights. I wanted to take pictures of the bare shelves in the super market but was advised not to do so. TV was limited to 2 hours a night (1 channel) with one hour devoted to the president. I never felt physically at risk, but you could see that it was the type of place where you could simply disappear and nobody would be able to find you.
Most big cities in the US have good and bad areas. NYC, LA, DC even here in SF are good examples. I never feel threatened when I visit any of them. Then again I have been to Harlem at night, ridden the NY subway at 4am, walked through Watts to go to a Raiders game, and visited some of the more transitional parts of DC at 2am. I guess that was risky but I didn't perceive any. The scariest travel experience was riding in a cab in Philly where the driver was on PCP.
