First of all, the term “detention” is sometimes equated to imprisonment, and in some cases, as Mr. Showler pointed out, people are kept in penal places. The recent influx of Roma people from Hungary, in fact, is probably mostly kept in hotels, and the space available for the Canadian-born who may need assistance is limited.
Detention is an interesting term for asylum seekers. It's sometimes considered that they are innocent until proven guilty, so why should they be held? It is not like a prison; they're free to leave any time they want. Any time the want to drop their claim and leave, they can. They're only being told that if they want to come and stay in this country, they have to put in a holding place until a decision is made if they deserve to be kept here.
I believe that widespread detention probably does make quite a bit of sense, particularly for the mass arrivals, because we're overwhelmed with numbers. We cannot screen them quickly. They pose a particular problem, not just in terms of large-scale criminal gang operations and possibly terrorists, but also in terms of sheer numbers. It draws resources off all sorts from other areas.