To quote more from the original article:
Some of the methodes used is social lockouts, verbal onesided quarrels, younger pilots declaring "non fit for flight" and refusing to fly with elder colleagues, signs with degrading texts in crewrooms, and degrading text on internal pilot bulletin boards (I assume they didn't mean this one?
).
I'm not sure who is on the "receiving" end of the bullying, it wasn't entirely clear in the article. Maybe both sides are.