I would put it somewhere between WTF and WTBS.
me: WTRF? you americans must have fucken awful media if you ever believed any of that shit.
P: Yeah, they apparently sent it to CANADA by mistake.
A more grandiose version of "wtf" (What the fuck).
Used when "wtf" just isn't enough to express one's surprise/shock/anger etc.
Commonly suffixed with numerous exclamation marks/question marks.
Capitalisation is often used to express further surprise/shock/anger etc, but is not essential.
A. "Dude, you should have seen the chick I nailed last night, horny as fuck"
B. "Cool, do I know her?"
A. "Yeah dude, it was your little sister."