How secure is HAL?

[Manuel Reimer]

Hello,

is a user or a program running with an unprivileged account able to get 
root access by plugging in an USB memory device with an executable file 
on it, which is owned by root and has the suid-bit set?

Who exactly sets the mount options for HAL? Is an unprivileged binary 
(like KDE) able to define which mount options are set?

How does HAL prevent from suid-root binaries? It doesn't seem like the 
"nosuid" mount option is used. Seems like HAL uses the "uid" option to 
"give all the files to the mounting user". Is this right?

At which place is this "uid" option generated and who sets the value for it?

Thanks in advance

CU

Manuel