Green’s Dictionary of Slang

a run-of-the-mill, average person.

1973		G.V. Higgins Digger’s Game (1981) 94: Those’re good items, you get the carriage trade with them, not just the hackers you get with Vegas.
1982		G.V. Higgins Patriot Game (1985) 84: Not even Ticker’s got the balls to go for that one for some hacker like he’s always putting up.
2009		L. McIlvanney All the Colours 190: This was part of golf’s appeal: physically, there wasn’t that much to choose between the Sunday morning hackers and their million-dollar idols.