Who is he?
Conan O'Brien replaced Jay Leno as host of Late Night, however, he was soon asked to come back and have his previous time slot.

A:
Jay Leno

Who is they?
Apple indicated that the Siri program would not be available for previous IPhones, but they were proven wrong when hackers were successful.

A:
Apple

Who is he?
Clinton wanted Obama to run for president because he could not win.

A:

Clinton