I like the term 'keyboard warriors' - it conjures up an image of someone with gritted teeth and a fierce frown bashing away on their keyboard, frothing at the mouth and shouting.
If I privately thought someone was 'talking bollocks', I wouldn't express it in that way. Id probably say instead, "I find that rather preposterous" or, "I disagree most strongly."
But then I'm quite ancient and have never used (or even heard) expressions such as 'talking bollocks'. Must have led a very sheltered life!