Early on there is a reference to the victim's laptop wallpaper being a picture of Sherlock in a dress. In Hackers (1995) Jonny Lee Miller's character lost a bet with Angelina Jolie's character and he had to wear a dress on their first date.
In this episode Jonny Lee Miller (Sherlock) is investigating and trying to catch a hacker. Early in his career he starred in Hackers (1995), playing a hacker who went by the handles "Crash Override" and "Zero Cool".
Everyone is based on the group Anonymous, an online collective of hackers who call themselves hacktivists and work as online vigilantes/warriors against wrongdoers. For example, they have been known to hack and report child pornographers to the police.
When Holmes views the camera surveillance footage from outside his house, in order to find the gum from the hacker named "Sucking Chest Wound", he trawls through the footage even though he knew exactly what time he turned up at the brownstone.
Strictly speaking there is no such college named Binghamton Polytechnic. There is, however, Binghamton University, which houses the Thomas J. Watson College of Engineering and Applied Science. It offers courses you'd find at a polytechnic university, e.g., mechanical engineering, electrical engineering, computer engineering, biomedical engineering, systems science and industrial engineering, materials science and engineering, and computer science.