F.Cuz finally joined twitter, and for Kan, he make a separate twitter account for himself.
Both of the account is legit since YeJun posted it on his cyworld.
Their twitter only follow Kan's twitter, so we can say it's legit as well.

Translation of Yejun's CY diary entry:

2010.06.04 17:57

FCuz twitter

@FCuz0108

Please find a lot

Translation: Adiana @ FocusedFcuz (here)
Sources: FocusedFcuz and Yejun's Cyworld