I think that it is good to be kind to forum members if it is their first offence at least.
In reality, most TOS violators aren't bad people - they simply haven't learned the rules of the forum they are in, or are used to a different style of communication, or even have issues with the forum's primary language. Some gentle steering will work wonders in most cases.
I would agree with rogerd's comments above and also add that sometimes forum posts (and email for that matter) can be misunderstood. Either the tone can come across wrong or there could be a double meaning. Also joking and sarcasm can sometimes be misinterpreted in a written context.
Like in the real world, diffusing a potential problem situation is always the best way rather than being a bull in a china shop.