#Eggplant Friday -- Instagram Pulls Black Junk ... TMZ TV

Apologies to Chris Brown ... and deepest regrets to B.o.B. -- but social media just got harder for nearly naked African-American dongs since Instagram put the kibosh on #EggplantFriday.

So, if you want to see a dude's junk online ... you'll have to scour the 900 million other sites.