What's my biggest worry at the moment? Strangely as it may seem, most of all I want all the Muslims adhere to their strict religious norms. Muslims are different from us but they've got religion making them live according to some Islamic laws. Most Muslims do it now and we see this as a huge irritant. Now, imagine for a moment these strict rules are being exploited by some smart tricky guys, by some creative beasts!
Matter of fact, presently some criminal and marginal elements (immigrants and youngsters of all sorts) in Europe convert into Islam with one sole motivation. They see Islam as sort of shield protecting them from European criminal laws! They are also well aware of the fact that in many European countries police are scary of any sorting it out with Muslims! And they just exploit this to realize some rotten schemes.
My college mate Peter used to be occasionally caught red handed in petty hooliganism and robbery. I was really amused to learn he's a Muslim now! Quite recently he was detained and taken to the police station as a suspect in some street robbery. The Muslim community of Hamburg he's now part of, demanded that they let him go!! I have no clue what he told them but they believed him. Peter was made to only pay some minor fine and that's all! You know, this is not the thing that can make me happy.