True, how you use them is the primary factor. How you manage the points of contact is everything. Honestly, I don't think 10,000 customers will be on my messengers. Also, if there was a DDoS attack, I don't think I would be on my messenger, instead I would be focused on fixing it. If I am on a messenger when that happens, you better believe I'm not going to be online and have that risk of all the customers coming at me and distracting me away from resolving the problem.