I have been thinking about this subject recently, especially in light of the recent incident, but beyond that also.
There are varied "philosphies" one can have regarding the subject of DIY projects and professional advice.
1) Only a professional tradesman should do the job. I won't help you do something you shouldn't do.
That's a legitimate opinion, but if it is your opinion, perhaps you are wasting your time and other's time even being on the forum.
2) Real World: People are GOING TO DO these things. Financial considerations as well as forces of nature ( aren't men DRIVEN to fix things?) dictate this.
Therefore, we will offer constructive advice and technical info to give you the knowledge and skill to do this without risk to life or property.
Now, there are times when the scope of the job in question is of such magnitude that the correct advice may be " you really should get a licensed professional for that". An example of that surely would be a job requiring work on live bus bars, or pulling the meter. Also, we occasionally see a question posted in which the homeowner by his statements and question is SO CLUELESS that we should also advise that this job is over your head and you will likely end up making a mess or hurting someone. It is possible to do this in a gentle way, possibly with explanations as to WHY this is the case.
It is always appropriate to remind people that permits and inspections are required, even if they do it themselves.