And by this, I don't mean "don't be a Ham" in the sense of hogging the spotlight or hamming it up, but rather this - don't be like Noah's son Ham. When Noah is drunk, and Ham discovers his father passed out drunk in his tent with everything exposed, instead of covering up this shame, instead of dealing with it privately, he runs, he points it out to his brothers - he makes a production out of the sin of his father.
Of course, Shem and Japeth are decent, they cover their father with a blanket, walking backwards into the tent so they don't even glance upon him in his inebriation. And, as you would guess, this is what is praised in the Scriptures, while Ham is cursed.
Don't be a Ham.
On line discussions can be intense, can be direct, can be fierce. That's one thing. Argue your points. If you think someone says something that is not theologically accurate, point out the error.
However, do not point out other people's personal sin. Do not bring up their mistkaes and errors of the past in order to discredit them (and thus sling mud on their arguments). It's not just an ad hominem argument - it's acting like Ham. Your theological point is not so important that you need to expose your neighbor's sin and shame to the world - go deal with it privately. Protect the reputation of the one who disagrees with you. Speak kindly of them, even if they don't "deserve" it - for you too have received from Christ that which you do not deserve.
All theology has as its ultimate goal the forgiveness of sinners. You cannot advance theology by using another's sin as a cudgel with which to beat them. This is good, for theologies and practices which have not forgiveness and mercy as their focus which permeates everything should not be advanced.