I think it's very wrong when people criticize and discriminate against immigrants in a general sense because you can't blame them for wanting to have a better life for them and their children. Especially considering all the history that countries like the UK and France have had in terms of colonies and such. If you're going to go to all these countries, take their resources, and not expect to give anything back then you are mistaken.
But, I do realize that immigrants can create economic and social problems at times, and that's where governments needs to play a more efficient role in determining who can live in their country, and to help integrate them into society. The big powerful countries should also focus on improving the standards of living from where the majority of these immigrants come from, so as to reduce the amount of people who want to move in the first place.