user@user-VirtualBox:/etc/init.d$ ./squid3 start
Rather than invoking init scripts through /etc/init.d, use the service(8)
utility, e.g. service squid3 start

Since the script you are attempting to invoke has been converted to an
Upstart job, you may also use the start(8) utility, e.g. start squid3
start: Rejected send message, 1 matched rules; type="method_call", sender=":1.77" (uid=1000 pid=2168 comm="start squid3 ") interface="com.ubuntu.Upstart0_6.Job" member="Start" error name="(unset)" requested_reply="0" destination="com.ubuntu.Upstart" (uid=0 pid=1 comm="/sbin/init")
user@user-VirtualBox:/etc/init.d$ ./squid3 start^C
user@user-VirtualBox:/etc/init.d$ ./squid3 restart
Rather than invoking init scripts through /etc/init.d, use the service(8)
utility, e.g. service squid3 restart

Since the script you are attempting to invoke has been converted to an
Upstart job, you may also use the stop(8) and then start(8) utilities,
e.g. stop squid3 ; start squid3. The restart(8) utility is also available.
start: Rejected send message, 1 matched rules; type="method_call", sender=":1.82" (uid=1000 pid=2226 comm="start squid3 ") interface="com.ubuntu.Upstart0_6.Job" member="Start" error name="(unset)" requested_reply="0" destination="com.ubuntu.Upstart" (uid=0 pid=1 comm="/sbin/init")