Elon Musk pushed debunked theories about Social Security on Monday while describing federal benefit programs as rife with fraud, suggesting they will be a primary target in his crusade to reduce government spending. The billionaire entrepreneur, who is advising President Donald Trump, suggested that $500 billion to $700 billion in waste needed to be cut. "Most of the federal spending is entitlements," Musk told the Fox Business Network. "That's the big one to eliminate."