From what was said in Anna’s dialogue, it becomes clear that Eric is a good guy!
Eric did not install hidden cameras throughout the house. Eric did not broadcast on the Internet everything that Max’s relatives are doing in the house. (I will continue the list later.)
Eric hired Anna for a good salary, Eric goes to restaurants with Anna, Eric listens to Anna's complaints about Max's behavior!
Eric, save the women from bastard Max!
Max doesn't trust his mom's new boyfriend, who is also her boss, because on their first meeting he threatened Max without provocation and informed Max that he was going make all the women in Max's life his play things and if Max does what he says he may get some table scraps.
Max realizes in order to save his family from Eric he needs to make enough money so his mom no longer has to rely on this creep.
So Max does the only thing his hormone addled brain can come up with given his available resources. He creates a voyeurism website showing what is going on in his home. "Sure this is a violation of their privacy but its better than what Eric plans for them." he reasons.
Eric even lies to Max mom claiming he saw Max steal money from him, and who does she believe? Not Max her son who she has know his whole life and would have an idea of his character but the guy she hasn't even known a month. (I could go on)
Max has to endure the abuse and mistrust until his aunt who has more experience and resources helps Max contact someone who can help him learn more about Eric's past.
With the information he obtains Max is able to turn the tables on the would be abuser of his family and drive him away.
Even though the corruption brought by Eric leaves lasting impressions Max still saved his family from a worse fate.
Max is the HERO!!!