“ enough to transmit the entire digitized Library of Congress three times every second” the engineer in me: compressed? With images? Or just raw texts?
From 2016:
"THE LOC’S DIGITAL COLLECTION currently comprises over 7 petabytes (7 million gigs) with more than 15 million items, including 150,000 print books. In an ideal future scenario, the LOC estimates that it could digitize a further 3-5 PB a year" [1]
So only the raw texts, probably. 10TB sounds about right for that.