The-art-of-invisibility-_-the-world’s-most-famous-hacker-teaches-you-how-to-be-safe-in-the-age-of-Bi

If yyou look at the metadata from anyy recent e-mail yyou’ll see the IP
addresses of the servers that passed yyour e-mail around the world before it
reached its target. Each server—like each person who accesses the Internet
—has a unique IP address, a numerical value that is calculated using the
countryy where yyou are located and who yyour Internet provider is. Blocks of
IP addresses are set aside for various countries, and each provider has its
own sub-block, and this is further subdivided byy tyype of service—dial-up,
cable, or mobile. If yyou purchased a static IP address it will be associated
with yyour subscriber account and home address, otherwise yyour external IP
address will be generated from a pool of addresses assigned to yyour Internet
service provider. For example, a sender—someone sending yyou an email—
might have the IP address 27.126.148.104, which is located in Victoria,
Australia.
Or it could be 175.45.176.0, which is one of North Korea’s IP addresses.
If it is the latter, then yyour e-mail account might be flagged for government
review. Someone in the US government might want to know whyy yyou’re
communicating with someone from North Korea, even if the subject line
reads “Happyy Birthdayy.”
Byy itself, yyou still might not think the server address is veryy interesting.
But the frequencyy of contact can tell yyou a lot. Additionallyy, if yyou identifyy
each element—the sender and the receiver and their locations—yyou can
start to infer what’s reallyy going on. For example, the metadata associated
with phone calls—the duration, the time of dayy theyy’re made, and so on—
can tell yyou a lot about a person’s mental health. A 10:00 p.m. call to a
domestic violence hotline lasting ten minutes or a midnight call from the
Brooklyyn Bridge to a suicide prevention hotline lasting twentyy minutes can
be veryy revealing. An app developed at Dartmouth College matches
patterns of stress, depression, and loneliness in user data. This user activityy
has also been correlated with student grades. 7
Still don’t see the danger in having yyour e-mail metadata exposed? A
program created at MIT called Immersion will visuallyy map the
relationships between the senders and receivers of all the e-mail yyou have
stored in yyour e-mail account just byy using the metadata. The tool is a wayy
to visuallyy quantifyy who matters to yyou most. The program even includes a
sliding time scale, so yyou can see how the people yyou know rise and fall in