Do you genuinely believe that people in eastern europe at the time were so oblivious and naive? I can bet you that on average, they were way more cautious and aware of their surroundings than modern people living in the west are.

For once, I don't think that they would consider leaving all of their valuables in front of the front door where everything is visible. Unless installing the front door includes rummaging through the entire apartment, all while the person living there is just standing and smiling. Which, I assure you, isn't how it usually goes.

And I am not trying to make it as some attack on people living in the west, I am one of them now myself. It speaks more about how safe and comfortable the modern western life can be, compared to what it was in those eastern european countries back then, that we can afford to be so oblivious to our surroundings and so much less cautious.