BT Home Hub 5 - USB stick as a server

[#1]

I have just read that the BT Home Hub 5 can be used as a server by plugging in a memory stick into the USB port.  My worry is about security.  If someone hacked into my router, could they see the files on the memory stick ?  Is this a real risk or not ?  I do not want to have to turn off my SSID because visitors could not then use my wi-fi.

[#2]

I'd say it's a very small risk and hiding your ssid wouldn't help with a competent intruder anyway.

I've got a hard drive plugged into my hub one.

[#3]

Thanks, I'll give it a go.