Can you tell me how relevant are IP layer attacks if we use internet through mobile phones? Suppose I get online, would I be visible to anyone on my same provider network? similarly, would anyone from a home computer with the same provider be able to do a SYN attack on me? Do u have to have firewalls on ur phone? Or do we take it for granted that the ISP gateway has it all and we are completely behind the NAT of the ISP?