Em,
Welcome to the group. I've read your story in the main SA/PA board, and your profile, and i must say you're incredibly calm. You seem to be handling the trauma of "My husband's poor decisions including prostitutes, constant porn, affair, lies, etc..."
After all thats gone on, unless he can see that the porn is the root of the problem,and that it has fuelled his poor decisions, then passwords will not keep him out, unless he wants to give it up.
He has a serious addiction, his thinking is impaired and he has minimalised and justified his actions for a long time. For him to move forward he needs to quit porn for good, not a few days. He needs to join a support group and get therapy to help him correct his unbalanced thinking. Otherwise, I'm sorry to say, the passwords will not help.
I do not say this to be malice, but an addict will find his fix where he can. I also changed all the passwords, and blocked out many sites for my h, before he was ready to commit to recovery. It unfortunately drove him to other sneaky behaviours, while pretending to not seek porn on our computer.
So be wary of doing this unless he is ready to commit to true recovery. Look after yourself, there's a long road ahead.

My computer at home is blocked from his access...and has been for 18 months...and will always be. According the psych's desk manual for treatment of these kinds of issues...the SA should never have access to a computer that is not in full view of any one home...or not be used at all. I made that decision long before reading the text. I dont put broken glass in the floor with a baby either. Ha! My H has no trouble with that at all. Before my doing that...he didn't even want to be home unless I was there because the computer was accesible and he feared that I might think he was using it. So, he asked that I sell it, block it, or disconnect from the internet. He has never requested the password...or suggested it was a problem. And even then, if I'm not home, he leaves our entry door open where he can be seen and the computer can be seen by me, or anyone dropping by.l His choice...not mine.

thanks for the welcome. I called my EAP at work and they emailed me info on this site.... what a blessing to find it. Yeah... I think I can see that the password deal for a few days won't really address the problem. I probably sound calm because I have been dealing with this for years and so it is old news for me. We dealt for a couple years with the affair issue in therapy, and I thought at times we had it behind us... only to find that wasn't the case on many levels. I'm only recently finding my voice and outrage in the whole thing... and seeing how clearly/directly porn relates to it all. I feel like I am going from porn passivity and downplaying to a freaking out freak out in my head...

Well, welcome to support from other freaks, all freaking out at many levels also :)