Americans, at least, have for some time used buster in speech or dialogue as a generic form of address. It has a range of tonalities, from light to affectionate to grimly confrontational.
Listen, buster, you can't beat me no matter how hard you try!
All right, buster, this time you're going down for the count.
As an aside, few people know that Jimi Hendrix's nickname, which his close friends used, was Buster. (The guitar duo of Rodrigo y Gabriela dedicated one of their tracks, Buster Voodoo, to him.)
Etymonline.com has this to say:
As a generic or playful address to a male, from 1948, American English.
The OED gives this:
Also used as a slang form of address, usu. friendly or slightly disrespectful; ‘mate’, fellow
and has a few citations beginning in 1948 (no doubt where Etymonline got its origin date):
1948 A. Seager Inheritance 174 ― ‘Hi-ya, buster. What’s new?’ he heard a woman’s coarse voice say. 1962 A. Shepard in Into Orbit 101 ― ‘OK, Buster,’ I said to myself, ‘you volunteered for this thing.’ 1965 P. Arrowsmith Jericho xix. 199 ― If you go on accusing me of attacking you lot, buster, you’ll have the police to answer to.
Yet it's used as a name much earlier (Buster Keaton, Buster Brown, etc.), and as the title of comic strips and even a play (see below). It's hard to imagine that the two uses are unrelated.
Indeed, Partridge's A Dictionary of Slang and Unconventional English (Supplement, page 1042), gives us this:
Buster. 'A name for anybody whose real name may or may not be known to the speaker. Usually but not necessarily pejorative. "Now listen here, Buster, this means trouble!"' (Leechman): Canadian: adopted, ca. 1920, ex U.S.
It's not clear to me how it got its present meaning from burster or buster (meaning "a gay, roistering blade"), and it certainly doesn't seem likely that it arrived from the meaning of a breaker of horses.
So I'm wondering. Did this just spring into the language fully formed, like Athena from the head of Zeus? Or is there a more mundane, less divine explanation?
Additional Information
I recently watched a documentary on Buster Keaton, which said he got his nickname in a certain way. While I can't reproduce that here, Wikipedia has something close to it:
According to a frequently repeated story, which may be apocryphal,[14] Keaton acquired the nickname "Buster" at the age of about 18 months. An actor friend named George Pardey was present one day when the young Keaton took a tumble down a long flight of stairs without injury. After the infant sat up and shook off his experience, Pardey remarked, "He's a regular buster!"[15] After this, Keaton's father began to use the nickname to refer to the youngster. Keaton retold the anecdote over the years, including a 1964 interview with the CBC's Telescope. In Keaton's retelling, he was six months old when the incident occurred, and Harry Houdini gave him the nickname.
Although the story may be apocryphal, it does clearly point to a usage that was current at the time.
