There's always an excuse not to do something to help. Usually it comes down to protecting our own way of life.
I'm sure this paranoid way of thinking was prevalent before and during the Second World War. As whole nations tried to flee the Nazi onslaught. Were there Nazi spies included among the genuine refugees? Maybe. But thank god for a few individuals who had more humanity than most and helped smuggle people to safety. They did the right thing for their "here and now".
to those people saying "these migrants are breaking the law" - carry on looking the other way of it makes you feel better.
to those people saying there might be a few terrorists among them. Could be true. But sometimes you have to take a risk to do the right thing. In any case they're unlikely to have weapons on them when they're rescued from a capsized boat or washed up one the shore. These people can be rescued and monitored.
far more dangerous I think is for some frustrated people of good will taking matters into their own hands and smuggling people to safety out of sight of the authorities. In those cases any terrorists could well gain entry completely off the radar.
to those that say we should send them back and concentrate on solving the problems in those countries at the root. That doesn't help anybody right now. The starving cold terrified family doesn't have the luxury of time.
we will always find a good reason not to help other people. The bottom line is, any of us could have been born in Syria or Iraq. Luckily for us we weren't. But that doesn't give us any moral "right" to the land we were born in through no personal skill of our own.
Humans. We're a selfish bunch aren't we?