Why is Giles Corey expelled from court? Why won't Danforth hear his evidence? Why is Corey arrested?

Danforth arrests Giles for contempt.

Giles, because he has been in lawsuits many times, assumes that he has rights in the court. He will not take Giles' evidence because he wants to see real evidence hearing that evidence from the men who have signed the document. Giles has told these people they will not have to come forward; he refuses to tell the judge the names of those who have signed the document, so Danforth refuses to hear the evidence. He is ultimately arrested because of his refusal to identify the people; he is cited for contempt of the court.

Giles claims that someone told him that he heard Putnam say that his daughter gave him a fair gift of land when she accused Jacobs. Giles refuses to name this person, however. When Danforth threatens Giles with contempt, Giles responds that this is not an official court session. Danforth arrests Giles for contempt.