# HG changeset patch
# User Christian Urban <christian dot urban at kcl dot ac dot uk>
# Date 1446799913 0
# Node ID 4a0bff167159eee21e39659632b6cb7ddb8f8cda
# Parent  b59fba19738ff1b51d6101a42143146070779976
updated

diff -r b59fba19738f -r 4a0bff167159 hws/hw04.pdf
Binary file hws/hw04.pdf has changed
diff -r b59fba19738f -r 4a0bff167159 hws/hw04.tex
--- a/hws/hw04.tex	Thu Nov 05 12:17:16 2015 +0000
+++ b/hws/hw04.tex	Fri Nov 06 08:51:53 2015 +0000
@@ -40,8 +40,10 @@
 \item What does it mean that the program \texttt{passwd} has the
   \texttt{setuid} bit set? Why is this necessary?
 
-\item Which permissions does the program \texttt{login}
-normally have and why is this needed?
+\item Under Unix (for example BSD Unix, MacOSX) the \texttt{login} 
+  programm has the setuid bit set. Why is this needed? In Linux
+  \texttt{login} does \emph{not} have the setuid bit set. What are
+  the consequences of this choice?
 
 \item The variable \texttt{PATH} is a shell variable in UNIX which
   lists all directories that should be automatically searched for a
diff -r b59fba19738f -r 4a0bff167159 slides/slides07.pdf
Binary file slides/slides07.pdf has changed
diff -r b59fba19738f -r 4a0bff167159 slides/slides07.tex
--- a/slides/slides07.tex	Thu Nov 05 12:17:16 2015 +0000
+++ b/slides/slides07.tex	Fri Nov 06 08:51:53 2015 +0000
@@ -304,7 +304,6 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mode<presentation>{
 \begin{frame}[c]
 \frametitle{Scare Tactics}
 
@@ -317,10 +316,7 @@
 website do not work. For example, you may have difficulties logging in 
 or viewing articles.''
 
-
-
-
-\end{frame}}
+\end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -430,6 +426,36 @@
 \end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\begin{frame}[b]
+\frametitle{FOI: New York Taxi DB}
+
+\begin{itemize}
+\item in 2013 somebody requested the Taxi DB (50GB of
+data, 173 million individual rides)\medskip
+
+\item data contained pickup and drop-off times, locations,
+ data that identified the taxi, amount paid + tip\bigskip
+ 
+\item no passenger data included\pause\medskip
+
+\item well paparazzi photos contain taxi licence (and sometimes
+photos are time stamped)\medskip
+
+\item a PhD student could identify rides of  
+  Bradley Cooper and Jessica Alba (more have been done
+  since then)
+\end{itemize}
+
+\only<2->{
+\begin{textblock}{5}(10,7)
+\includegraphics[scale=0.15]{../pics/newyorktaxi.jpg}\\
+\end{textblock}}
+
+
+\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+
 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%