One can set the disk label length to be a string as long as you like. This can result in crashing the client or world corruption as it cannot fit within an NBT Tag:

• Create a new computer and place a disk drive + disk next to it.
• Set the disk's label to ("x"):rep(1e7).
• My game hangs on a client world. Attempting to close Minecraft results in encoded string to long: 10000000 bytes when trying to serialise NBT.

It is also possible to use \0 within labels which causes issues with Sponge. Whilst I realise Sponge is not officially supported by ComputerCraft it would be nice if labels were limited to the printable, ASCII range.