Tax write off read additional info?

Ok so my brother is into self employment and he basically thinks if it deals wit work he can write it off in his taxes he rents a car for work that's 1000 dollars a month and then he buys clothes for work (these are just like regular clothes but he says for work cause its music and he can relate wit the clothes) also he buys food he says work and rents a place again for work and his phone bill also what in the heck is this milarky how can you write off everything and get all Ur money back that just sounds like playing our hard payed for taxes that we pay for everyday there has got to be something to protect us Americans from people like my brother who scam taxes ?