Yeah, there is definitely stealth brokering going on and I believe that what the network feels about it depends on how much they care about their merchants. Stealth brokering is a massive source of fraud and any network that doesn't care about stealth brokering really doesn't care much about the merchants for which they are supposed to be working.
Why is stealth brokering a massive source of fraud? Because it is typically employed by third and fourth tier networks that are unwilling/unable to reach out and make deals with other networks or with merchants directly. They are unwilling/unable to make deals because their network is nothing more than a source of affiliates that have either been banned from other networks or can't get approved into other networks. They know (or they are too ignorant to realize) that the leads they deliver are nothing but garbage and they hope to deliver leads until they are caught by the network from which they are sourcing the offers. Once they are caught, they simply grab the same offers from another network who doesn't care about stealth brokering.
Networks that knowingly allow stealth brokering know the leads they receive this way are total shit. Continuing to send these kinds of leads to their merchants makes them not much different that the third/fourth tier networks that deliver the shit leads. All they really care about is making a quick buck at anyone's expense. While everyone's goal is to make as much money as possible in as short of a period of time, there are ways to do it where everyone wins (merchant, affiliate, network). Sadly, the networks that allow stealth brokering only care about one part of that equasion: the network.
Note that I'm only talking about stealth brokering. Traditional brokering between networks can work well for all parties involved because there is communication involved. The key part that is missing from stealth brokering.