Media.net Ad Network is indeed a legit network and they WILL pay their publishers their earned money.
If you read through those forum saying they were banned. Most of them have the majority of their website traffic
coming from other countries other than the USA.
Media.net wants traffic to come from the USA. At least the Majority of it. If your website traffic is mostly coming from other countries such as Vietnam and India then they'll freeze your account.
If your website has majority of website traffic from USA then you will get paid your earnings.