If you are installing from a USB stick, it should be filtered from consideration as an installation target in all ways. This seems to be working at present for livecd-iso-to-disk written media, but not dd-written media. These appear on the Installation Destination screen as an available target device, which should not happen.

Here is blkid output from the F19 Beta netinst image dd'ed to a USB stick:

[root@adam Beta-RC4]# blkid /dev/sdd
/dev/sdd: UUID="2013-05-23-00-43-30-00" LABEL="Fedora 19-Beta x86_64" TYPE="iso9660" PTTYPE="dos" 
[root@adam Beta-RC4]# blkid /dev/sdd1
/dev/sdd1: UUID="2013-05-23-00-43-30-00" LABEL="Fedora 19-Beta x86_64" TYPE="iso9660" PTTYPE="dos" 
[root@adam Beta-RC4]# blkid /dev/sdd2
/dev/sdd2: SEC_TYPE="msdos" LABEL="ANACONDA" UUID="E70E-7C39" TYPE="vfat" 
[root@adam Beta-RC4]# blkid /dev/sdd3
/dev/sdd3: UUID="26a0e7d8-f305-3d87-8e53-2317fd190b7e" LABEL="ANACONDA" TYPE="hfsplus" 

and from an F19 Beta desktop live image dd'ed:

[root@adam Beta-RC4]# blkid /dev/sdd
/dev/sdd: UUID="2013-05-23-03-45-50-00" LABEL="Fedora-Live-Desktop-x86_64-19-Be" TYPE="iso9660" PTTYPE="dos" 
[root@adam Beta-RC4]# blkid /dev/sdd1
/dev/sdd1: UUID="2013-05-23-03-45-50-00" LABEL="Fedora-Live-Desktop-x86_64-19-Be" TYPE="iso9660" PTTYPE="dos" 
[root@adam Beta-RC4]# blkid /dev/sdd2
/dev/sdd2: SEC_TYPE="msdos" LABEL="EFI" UUID="BE8A-3C58" TYPE="vfat" 
[root@adam Beta-RC4]# blkid /dev/sdd3
/dev/sdd3: UUID="9174fb32-f7b1-31fa-8b5e-51c153e98f55" LABEL="Fedora Live" TYPE="hfsplus"