The horrified reviews of this film confound me - Scorcese has shot movies with a persons head getting crushed in a vice, multiple gunshot wounds in graphic detail, and glorification of organized crime. His pedigree alone should give one pause before bringing in preteens and grandparents to see his latest work. DiCaprio's last film had him starring as a sadistic racist slave owner in Django Unchained, where violence was shot like soft core pornography. Apparently people ignored all of this and bellied up to the bar for this mature take on the continued excesses of the finance industry.
As many here have said, there is extensive sex and nudity in this film. Children should not be exposed to this. Children should also not be exposed to Casino, Goodfellas, The Departed, Gangs of New York, Mean Streets, or Taxi Driver. Movies are rated for a reason...in the Age of Google, if you walk into an R Rated flick uneducated or prepared, thats not the films fault, or the ratings board, thats yours.
For adults who like morally ambiguous studies of what the hyperreal American Dream looks like, and who are more concerned about violence than nudity, this film is great. Highly recommend. It is not for kids of ANY age. If you want a morality play, this aint it.
For those traumatized by it, use Google next time. Be somebody.