In Terminator Salvation, we see Skynet capturing humans and herding them in its main facility in San Francisco. What was the purpose of this exercise? Was it trying to locate Kyle Reese? Or was it using the humans as a shield against any resistance attacks?
Skynet needed the humans "to do lab testing on their stem cells. This research on humans led to the creation of the Series 800 Terminator." That quote is from Terminator Wiki here.
Update: According to a quote from Kyle Reese in the original Terminator movie, Skynet collected humans in concentration camps for mass disposal, also using some humans as workers:
- Kyle Reese: "Most of us were rounded up, put in camps for orderly disposal. (pulls up his right sleeve, exposing a barcode) This is burned in by laser scan. Some of us were kept alive... to work... loading bodies. The disposal units ran night and day."
Shiz Z. was originally correct. In salvation when Marcus syncs with the mainframe you can see him reading newspaper clippings about the doctor.
If you read them carefully, they say that she was pioneering stem cell research for tissue regeneration. This is used by Skynet to make the T800's infiltration units look human. Although never directly stated, it can be implied that the humans being round up in this particular facility are being used either for slave labor until they expire, or as a human hosts for the machines to do some wizardry so they can grow more tissue for the T800's.