Internet Filtering Worldwide

The Technologies of Filtering and
Their Unintended Consequences

Agenda

“Who”: Country-based filtering

“What”: Typical targets of filtering

“How”: Filtering technologies

DNS Redirection Example (China)

DNS Redirection Example (China)

Granularity

Granularity of blocking

Granularity of blocking

Selected filtering “mistakes” (China)

Transparency

Transparency of the block list

Approaches to transparency

Approaches to transparency

Practical concerns

Blocking by which country?

How to tell if your site is blocked

What to do if your site is blocked

Email filtering

Email filtering

How to tell if your emails are blocked

How to tell if your emails are blocked

What to do if your emails are blocked

What to do if your emails are blocked

Internet Filtering Worldwide

The Technologies of Filtering and
Their Unintended Consequences

Research, articles, listings of specific blocked sites:
http://cyber.law.harvard.edu/filtering