"A Big Fuck You" Is a way of saying Fuck You to a greater degree, to really let that person know they gon fucked up and your pissed off about it because sometimes just a regular Fuck You just wont cut it. "A Big Fuck You" can be delivered in two main ways, verbally and phisically. Verbally can also be online or on the phone and physically usually refers to sports competetions, pranks and other in your face Fuck You's. "A Big Fuck You" can be given or recieved.
When DG sorority execs threaten to "Cunt Punt" their members. Thats a Big Fuck you.
When Lebron swats the fuck out of Tiago Splitter in the 2013 Playoffs. Also a Big Fuck You.