Factual error: When Mark types email addresses in to tell people about facemash, he writes to several people @harvard.edu. At the time the movie takes place, undergraduate email addresses were all of the form email@example.com. Furthermore, the network brought down by facemash would have been referred to as the FAS network. (FAS stands for Faculty of Arts and Sciences; the eponymous network covered all buildings within the College and Graduate School of Arts and Sciences.).
Factual error: In the beginning, a Dunkin' Donuts cup is shown with the pictorial logos representing "America Runs On Dunkin'. This ad campaign was not begun until 2006.
Factual error: At the conclusion of the film it is stated on screen: "Ayrton Senna died aged 34. In the aftermath of his death, the FIA appointed Ayrton's friend Prof. Sid Watkins to improve safety in Formula One. There has not been a fatality in Formula One since." While it is true that no driver has been killed at a Formula One Grand Prix since Senna, there were crashes at the Italian Grand Prix in 2000 and the Australian Grand Prix in 2001 which resulted in the deaths of marshals. (01:37:50)