He later received his master's degree in the same subject from Stevens Institute of Technology in Hoboken, New Jersey, while working at Bell Labs and later at Bellcore.
The phrase "We are all Rich Rosen" was coined during this period and persisted as a Usenet catchphrase for a number of years.
Among his contributions: He was known for participating in (some would say "inciting") numerous flame wars with other Usenet contributors, including the notorious Brahms Gang, a pair of equally loquacious mathematics graduate students from Berkeley (Gene Ward Smith and Matthew P. Wiener) who posted from a server named brahms.berkeley.edu.
He was also known for his variety of frequently-changing .signature files, including: The volume and content of Rosen's postings evoked strong reactions in both advocates and detractors.
He hosted his own popular "Monty Python home page" that was cited by both Lycos and the Global Network Navigator.