Men's Rights

Regarding the feminism assignment today the article about "Just who are men's rights activist"?  They stated even if the man is the primary care giver of his kids he can still lose at gaining custody to a woman.I feel the law is designed that way. I have seen it first had, I have a friend who had his daughter from birth because the mom was on drugs. When the daughter got a little older the mom tried to come back into the child's life after being clean from drugs for a year. The father took the case to court and the mother still was able to get joint custody. The father was unable to get full custody although all these years the mother was an unfit parent. I believe in certain situations men have no one to defend them. But its never spoke upon because their man and society feels like they should just deal with it.