IPV6 Link local addresses are autoconfigured addresses based on the devices MAC address.
The biggest problem is that the kernel has fe80::0/10 routed with every interface, so if you ping a link local address it doens't know which interface to use.
The way to get around this is to tell the program which interface to use.
etc.
This, and other gotcha's with IPv6 is discussed in IPv6LessonsLearnt.
See IPv6Addressing, Compare SiteLocal and GlobalScope addresses.
6 pages link to LinkLocal: