Not sure what you mean? Are they required to track our information on who bought what accessories? No, not by law. However, as with the original Red Dawn, the bad guys used the 4473 forms to find the gun owners. So, with on-line sales, yes, sellers maintain the information on non-firearm sales, but I would think it would take a court-order to get at them.
I would imagine CTD could not be trusted to not simply turn over the information.
Consider how google just hands things over without subpoena.
Who to trust?