Neo has this feeling that bothers him that "something is not right with the world". He tends not to follow rules that he feels as limits put on him. The strangeness of this feeling he can't articulate that he feels that these limits are put on him on purpose, one that is intentionally hidden from him. The limits won't be bothering him if there were reasons for them, but it's likely from his attitude that all he got for his questions were menace, threats and opressionoppression (or been ridiculed).
The hackers were already discussing these topics - it was so hot that the chat room itself is called "The Matrix". It seems that the Matrix and Morpheus were connected to some new game but some still beleivedbelieved in them (much like the Publius Enigma). It's likely that it was like an urban legend (about the hidden control, of course), connected to Morpheus. Neo's comments imply that he already knows and is far more serious about these.
Alternatively, it could be that he knowknows Morpheus first because he is known as a terrorist (the movie allows him to be even famous while this latter draft excerpt would imply that Neo was hacking his way to the information on him). Neo as a hacker, is likely to consider/explore alternatives to official explanations to terrorist attacks (or simply view most news as cover stories right from the start) and thus get familiarized with Morpheus.
It's also possible that simply it's known that Trinity is connected to Morpheus and Neo knows about "her/him" (The Trinity). It would be natural from Neo to do a search on Morpheus. Morpheus is also called "legendary" in the draft, whatwhich would be enough on its own merit.
Either he just started to look for similar thinkers, or heard about the Matrix first then Morpheus, or vice-versa, he started to study the latter two. Morpheus is trying to free minds, while also looking for theThe One, so it's likely that he tried to hint as much information about the Matrix as it's humanly possible.