Internet Filtering Worldwide:

The Technologies of Filtering and
Their Unanticipated Consequences

Focus: Technical, not “preaching”

Agenda

“Who”: Country-based filtering

“Why”

“What”: Typical targets of filtering

“How”: Filtering technologies

Granularity

“How”: Granularity of blocking

“How”: Granularity of blocking

The effect of technical happenstance on filtering granularity

The effect of technical happenstance on filtering granularity

Selected filtering “mistakes” (China)

Transparency

Transparency of the block list

Approaches to transparency

Approaches to transparency

The effect of technical happenstance on filtering transparency

The effect of technical happenstance on filtering transparency

Implementation decisions,
practical choices

To consider when selecting a filtering implementation

Implementations: comparison

Filtering errors: a taxonomy

Errors: inevitability

Errors: reducing errors

Block lists: build versus buy

Big picture: where is filtering going?

For further discussion

Internet Filtering Worldwide:

The Technologies of Filtering and
Their Unanticipated Consequences

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