Thank you for that John Allison link, Nicky. I found it to be very helpful in answering my question!
By the way, I do not like emotional arguments, like calling intellectualammo a "scumbag." I find it much more useful/convincing to elaborate on why it is wrong:
In objectivism, an act is wrong if it is self-destructive. Nicky mentions that being deceitful is self-destructive because "people will learn to avoid your business." Also, Nicky's link mentions that honesty is the foundation to human relationships and that it should be a person's goal to improve their personal values. Therefor