> By the way, I'm pretty sure none of the actual AWS datacenters are in Reston proper.

Pretty sure you are right. The physical AWS data centers I know of in Reston area are:

4 DCs on Smith Switch Rd in Ashburn, VA

2 DCs (IAD54 and IAD67) elsewhere in Ashburn, VA

3 DCs on West Severn Way in Sterling, VA

3 DCs on Dulles Summit Ct in Sterling, VA

2 DCs on Prologis Dr in Sterling, VA

2 DCs on Relocation Dr in Sterling, VA

2 DCs (IAD69 and IAD76) elsewhere in Sterling, VA

1 DC in South Riding, VA

4 DCs on Westfax Drive in Chantilly, VA

3 DCs on Mason King Ct in Manassas, VA

2 DCs elsewhere in Manassas, VA