What is the meaning of the line in italics ?
ONE has to admire these protesters in the city for the sacrifice they have made to voice their opinion. am sure many have sacrificed study, so risk failing exams; others have lost wages from their employment and, when they do finally return home, may find that their squats have been boarded over.
This is a good question. I can see why you have a question about the word "squat." The word, "squat" is not one that we use of often.
A squat is a place where a squatter lives. A squatter is a person who lives in a place where he or she does not have legal rights. However, in certain contexts, such as in New Zealand and Australia, a squatter is a person who is a tenant of a tract of land that is owned by the Crown.
Within the context of this passage, the person is saying that the people who support the Occupy Movement are heroic in their sacrifice. They sacrifice school and work. Moreover, some of them even sacrifice their "homes." These people are probably homeless and living in makeshift shelters. So, when they return, they may see their "homes" boarded up. Sacrifice is underlined again.