The line-item veto permits the president to block specific spending measures without rejecting an entire piece of legislation.

CNN: AllPolitics - Line-Item Veto

Scroll down to "Custom, " and from there you can block specific people from seeing your Timeline post, and consequently littering it with inane comments.

CNN: Dueling online over 'Call Me Maybe'

That policy allows it to block content in specific countries if tweets violate local laws.

BBC: Twitter blocks neo-Nazi account to users in Germany

Say if one telecom company owns specific content, they may block out someone else's content.

NPR: Net Neutrality Battle Goes to Washington

Application Control identifies numerous programs and applications with the ability to block or limit employee usage based on their specific business needs.

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Instead they are created by the system's network when a specific amount of computer work, known as a "block" has been completed.

BBC: Rewards set to halve for digital money miners

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