Can iPhone SE with carrier Straight Talk be unlocked?

I looked a little and seems they have strict policy on it. But, also said they changed it. I'm going to buy a iPhone SE from eBay.

They are required to do this as per Federal law, once any contrast you have with them for the phone and/services is paid.

If you are not a current customer, they will NOT unlock a used phone, in fact none of the carriers will, if you are not a current customer and did not get the phone through that carrier. So if the seller has not had the phone unlocked, you will have to pay an unlocking service to do the job.