Who was the chap who crossed the Channel in an International Canoe, and returned with a hitcher who had never sailed before? That hitcher must've really needed to get across.
I happily pick up hitcher students on the road, not that you see any these days having all been warned by their parents that only nutters and murderers pick up hitchers.
If they were English possibly yes, foreigner's definitely not the cons outweigh the pros so much. I can understand a brit running out of cash and needing a ride home, but if you plan to travel abroad and have no means I would worry.