There are some creative things to be done ("Where there's a will, there's a way"), but realistically, all someone could really do is DDoS you.
This isn't much of a risk these days, since if someone wants to DDoS you, they are going to figure out your IP and do it regardless (for example" someone mentioned being able to get it just by knowing your Skype - this is true - you type the person's Skype into a Skype Resolver and BAM, you have their IP).
You could use any number of free proxy websites to log into your account, if you really just don't want them to have it. You could also download HotSpot Shield, or any other program with the same function.
TL;DR Don't worry about it.