This famous photograph called Vive La France is part of a new exhibition at the Leopold Museum - "Nude Men".
The museum has agreed to cover the penises with red ribbon due to public outrage:
"We didn’t realise that many, many people would be really upset or really angry in a way that we are also afraid about security, about protection of the visitors of the museum” explained Klaus Pokorny, a spokesperson for the museum, as quoted in Reuters.
“Many people told us that they wanted to or had to protect their children,” he added about the response to the naked advertisements. “Some had warned that if we won’t cover it they would go there with a brush and they would cover it with color. Already somebody did that.”
Genital shame is universal.