Yes, and there is a lot of mentally ill people on the web, not just Buddhist web forums. And there's also people who are not mentally ill but are just plain dishonest, intentionally or not, as some people are used to lying so much it's become auto-pilot for them.
I think being aware of how we lie to ourselves is good practice and try to reduce it as much as possible, as it only blocks us from understanding the dhamma.
Then the Blessed One, having left a little bit of water in the water dipper, said to Ven. Rahula, "Rahula, do you see this little bit of left-over water remaining in the water dipper?"
"Yes, sir."
"That's how little of a contemplative[2] there is in anyone who feels no shame at telling a deliberate lie."
Having tossed away the little bit of left-over water, the Blessed One said to Ven. Rahula, "Rahula, do you see how this little bit of left-over water is tossed away?"
"Yes, sir."
"Rahula, whatever there is of a contemplative in anyone who feels no shame at telling a deliberate lie is tossed away just like that."
Having turned the water dipper upside down, the Blessed One said to Ven. Rahula, "Rahula, do you see how this water dipper is turned upside down?"
"Yes, sir."
"Rahula, whatever there is of a contemplative in anyone who feels no shame at telling a deliberate lie is turned upside down just like that."
Having turned the water dipper right-side up, the Blessed One said to Ven. Rahula, "Rahula, do you see how empty & hollow this water dipper is?"
"Yes, sir."
"Rahula, whatever there is of a contemplative in anyone who feels no shame at telling a deliberate lie is empty & hollow just like that.
"In the same way, Rahula, when anyone feels no shame in telling a deliberate lie, there is no evil, I tell you, he will not do. Thus, Rahula, you should train yourself, 'I will not tell a deliberate lie even in jest.'
"What do you think, Rahula: What is a mirror for?"
"For reflection, sir."
"In the same way, Rahula, bodily actions, verbal actions, & mental actions are to be done with repeated reflection.
"Whenever you want to do a bodily action, you should reflect on it: 'This bodily action I want to do — would it lead to self-affliction, to the affliction of others, or to both? Would it be an unskillful bodily action, with painful consequences, painful results?' If, on reflection, you know that it would lead to self-affliction, to the affliction of others, or to both; it would be an unskillful bodily action with painful consequences, painful results, then any bodily action of that sort is absolutely unfit for you to do. But if on reflection you know that it would not cause affliction... it would be a skillful bodily action with pleasant consequences, pleasant results, then any bodily action of that sort is fit for you to do.
"While you are doing a bodily action, you should reflect on it: 'This bodily action I am doing — is it leading to self-affliction, to the affliction of others, or to both? Is it an unskillful bodily action, with painful consequences, painful results?' If, on reflection, you know that it is leading to self-affliction, to the affliction of others, or to both... you should give it up. But if on reflection you know that it is not... you may continue with it.
https://www.accesstoinsight.org/tipitak ... .than.html