Basically, I have that same account logged in on my PS4 system and set as my Main Account, I created another PSN account for other people to play with me in co-op games which require a second account logged in to keep progress and such. Well, as I have about a year of PS Plus remaining on my Main Account and it is still logged in and sharing it's Online access with the other accounts, I can still go online on my second account and play; for example, I've been playing Ghosts for hours now and it still works.

I've also contacted Sony's Support and they told me that I would not be able to play online with that account anymore, guess it was only with that account; they also told me I would not have access to my games library, and thus all of my bought games would be locked for download, I clicked on Watch Dogs and it still took me to the game [but I haven't started it just yet(I was playing Ghosts hahaha)]. Well, they also told me that if I tried playing downloaded games from my banned account with my other account, there'd be a chance that I could get banned, it's kinda obvious they told me that because they just want us to get fucked up and never play their shitty games again for free, so I'd have to pay again, that would never happen.

Resuming all of my text, well, if you get banned on the PS3, you can still go online with another account logged in on the same PS4 console as the banned one which has online access and is set as the main account. Good thing Sony doesn't delete our banned accounts.

Something I've also noticed, if the PS4 detects an account with PS Plus logged in as the main one, you can play with other accounts online with only one account having PS Plus, so if we could ever mod the PS4, we could trick the system into thinking that there is an account with Plus, so we would have online access without paying for it. I don't know if it is possible too, but if we could simulate a download on a PS4 account and it logged that game to the library so we could download it again, then we could have modded accounts and transfer them over every non-modified console to download any game for free.