The whole thing is rather frustrating, because there are 'real' refugee's and what I would call economical immigrants, so yeah, there are very bad apple's amongst the refugee's and unfortunately, it is often the large group of single men that arrive, you see comparatively few groups families, women/children, do I know refugee's that actually work to fit into the new place they have arrived, sure, but I've also seen the other side of it, and the first do not particularly enjoy the second group, those that bring trouble, the first group want a new life. The second group, who knows.
The problem is, how do you filter that? because bad apple's arrive with families and without, the real refugee's if you will, how do you only let them through? vetting can only do so much when 'papers' are easily forged or simply 'lost'
But all that said, especially america, has a LOT worse problems then refugee's/immigrants, Europe is having issues, yes, but population wise, the countries of Europe are also small, and take in large amounts of refugee's, but yeah, it comes down to how do you sort through people to find out the real reason they are in a country?