While this is certainly a well-intentioned idea it's problematic for several reasons (I'm not saying it's impossible but anyone trying address this issue should

While this is certainly a well-intentioned idea it's problematic for several reasons (I'm not saying it's impossible but anyone trying address this issue should be aware about these problems): There have been high-profile abuse cases with Airbnb already and Airbnb is a service mostly used by rather well-off people from developed nations with some sort of profile and identity record. Authorities are struggling already with ascertaining the nationality of many refugees, let alone their identity. The by far largest share of refugees certainly won't be coming to Europe for committing crimes but it's unavoidable that there'll be a fair share of strange people, criminals and terrorists, too. If you happen to unknowingly accommodate one of those who'll be liable for potential damages to your property? If the person commits a crime you're effectively hiding a criminal. So, your good intentions good ultimately even might have you end up in person. What I could imagine is requiring participants in such a service to at least have some sort of official documents before being allowed to apply. That doesn't really solve the underlying problem, however, which is that there currently is no sufficient infrastructure for registering and accommodating all those problem.