So the illegal here is the scraping or blasting the @faceb0ok emails ?
I guess that you are asking whether FB scraping is illegal, and this is your answer from the horse's mouth:

Btw, everything is important there, but read point #14 very carefully...
Code:
https://www.facebook.com/apps/site_scraping_tos_terms.php
One of my dearest friends got punished back then for whatever he did to a giant company... now some of my other friends (may be many of those) are going the same way and
too openly. Who would know if they do it in secret? (no one, or not too many). But as they do it openly, people who matter are focusing on to this, and so they could be in similar dangers because the target is one of the biggest companies in the world, and so, out of deep concerns, I wrote the above piece. Please don't do it, there could be your dear ones and highly-placed ones (I don't know, there could definitely be the one who is working at a very high place among the family) who could get needlessly and negatively involved, especially if you are a US or its friendly nation's citizen. The investigators will find that angle too... F~B is cracking on everything all the time to save its reputation as one of the top entities in the world, and they make the culprits pay so that others like him/her take notice in future and stay away afap... Do you have a chance against them? Think...
People who do it secretly are not easy prey for f~b, but those doing the same this openly--- be warned. I'm your friend, and hence this concern... the thread is just 2 days old, may be little less than that if you're on the US side. This will surely go viral soon, and then those initially slow moving wheels WILL gather speed, in this direction definitely, imo.