Libertarians are supposed to be supporters of personal freedom, so how do you square that with not supporting the freedom of people to live and work where they want? Why do open market principles suddenly not apply when it comes to the labour force? You should merely consider yourself greedy and a bit of a hypocrite if you believe that you should have all the personal freedoms you desire, but no one else should. You can't even make the argument that you should be able to protect what you've earned, since you didn't "earn" being born within a certain set of borders.
I've seen what migrants are doing in Europe. Last year in Germany there was a young girl, who just got a degree and went to work in social services. In her first year of work she got attacked and killed by a migrant, during an interview. The same year a policewoman in Berlin was attacked by a migrant with a knife. Just watch some clips, like that viral one where a migrant tells a funny (at least to him) story of how they abducted a young girl, a virgin, and then raped her in the housing complex the government has provided for them. If that happened to my daughter I'd have gone there and butchered them like the animals they are. Or read some articles about the attacks during New Year's Eve: http://www.dailymail.co.uk/news/article-3773014/At-four-women-sexually-assaulted-immigrant-men-rampage-party-Germany-chilling-echo-New-Year-s-Eve-attacks.html
Maybe you, and I'm talking to the social liberals here, who think you can live alongside those people, should pay a visit to Sweden or Southern France? Maybe spending a day in a refugee housing area would give you a perspective.