That's not a particularly nice gesture in a lot of parts of Europe.
Another gesture that mediterraneans don't like is our open hand salute for "hi" or "bye".
Well, since I'm neither in Europe, nor European, I can only hope that any Europeans coming across my post, understanding that no one can learn the meaning of every gesture and phrase in every culture, would take into account my intent. I know that if someone gave me the middle finger salute, and I learned that in their culture it meant "jeez, you are a wonderful person," I would not be offended in the least. I do not expect people from other parts of the world to be familiar with all our cultural symbolism. I don't think they should expect me to be familiar with everyone else's.