隔空喊话

gé kōng hǎn huà

to converse with sb by shouting from some distance away

(fig.) to say sth intended for the ears of sb who is not in one's presence (often, by making a public statement or by posting online)

隔

gé

to separate

空

kōng

empty

喊

hǎn

to yell

话

huà

old variant of 話|话[hua4]