[SOLVED] Need a root access to mount USB flash drive

I clicked my USB flash drive in Dolphin and then this message pop up.

Why it's like this? Isn't it usually a normal user could mount a USB flash drive?
sdb1 (sole USB flash drive partition) is formatted as vfat.

Why it's like this? Isn't it usually a normal user could mount a USB flash drive?
sdb1 (sole USB flash drive partition) is formatted as vfat.