to screen a call is to look at the caller ID of an incoming call and decide whether or not to answer it.
to have your call screened is similar to being side buttoned
mary: hey your phone's ringing who is it?
sven: (looks at phone) oh my gawd it's my cokehead ex.
mary: eeww you don't want to talk to him. screen that shit.
sven: yeah no kidding. (presses ignore) scrrrrrreenin that!