Description of problem:
It happened when I tried to open Shotwell and it loaded pictures from my "Pictures" directory (in my home directory). I don't know how serious a problem this is.
SELinux is preventing /usr/bin/shotwell-video-thumbnailer from 'append' accesses on the unix_stream_socket unix_stream_socket.

*****  Plugin leaks (86.2 confidence) suggests  ******************************

If you want to ignore shotwell-video-thumbnailer trying to append access the unix_stream_socket unix_stream_socket, because you believe it should not need this access.
Then you should report this as a bug.  
You can generate a local policy module to dontaudit this access.
Do
# grep /usr/bin/shotwell-video-thumbnailer /var/log/audit/audit.log | audit2allow -D -M mypol
# semodule -i mypol.pp

*****  Plugin catchall (14.7 confidence) suggests  ***************************

If you believe that shotwell-video-thumbnailer should be allowed append access on the unix_stream_socket unix_stream_socket by default.
Then you should report this as a bug.
You can generate a local policy module to allow this access.
Do
allow this access for now by executing:
# grep shotwell-video- /var/log/audit/audit.log | audit2allow -M mypol
# semodule -i mypol.pp

Additional Information:
Source Context                unconfined_u:unconfined_r:thumb_t:s0-s0:c0.c1023
Target Context                unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
                              023
Target Objects                unix_stream_socket [ unix_stream_socket ]
Source                        shotwell-video-
Source Path                   /usr/bin/shotwell-video-thumbnailer
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           shotwell-0.14.1-1.fc19.x86_64
Target RPM Packages           
Policy RPM                    selinux-policy-3.12.1-69.fc19.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     (removed)
Platform                      Linux (removed) 3.10.4-300.fc19.x86_64 #1 SMP Tue
                              Jul 30 11:29:05 UTC 2013 x86_64 x86_64
Alert Count                   4
First Seen                    2013-08-08 23:39:24 EDT
Last Seen                     2013-08-08 23:39:25 EDT
Local ID                      a1678a7e-0893-47d3-84ba-713ec6d6e711

Raw Audit Messages
type=AVC msg=audit(1376019565.976:837): avc:  denied  { append } for  pid=12628 comm="shotwell-video-" path="socket:[24900]" dev="sockfs" ino=24900 scontext=unconfined_u:unconfined_r:thumb_t:s0-s0:c0.c1023 tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=unix_stream_socket


type=SYSCALL msg=audit(1376019565.976:837): arch=x86_64 syscall=execve success=yes exit=0 a0=7f3c84013ad0 a1=7f3c8401aa30 a2=7fffb5d570f8 a3=25 items=0 ppid=12580 pid=12628 auid=1000 uid=1000 gid=1000 euid=1000 suid=1000 fsuid=1000 egid=1000 sgid=1000 fsgid=1000 ses=1 tty=(none) comm=shotwell-video- exe=/usr/bin/shotwell-video-thumbnailer subj=unconfined_u:unconfined_r:thumb_t:s0-s0:c0.c1023 key=(null)

Hash: shotwell-video-,thumb_t,unconfined_t,unix_stream_socket,append

Additional info:
reporter:       libreport-2.1.6
hashmarkername: setroubleshoot
kernel:         3.10.4-300.fc19.x86_64
type:           libreport