Ensuring that bots are blocked means presenting a test that the software cannot complete.

FORBES: Artificial Intelligence Will Defeat CAPTCHA -- How Will We Prove We're Human Then?

When cardiac CT angiography is being used appropriately -- meaning, for example, in people with chest pain suggesting blocked heart arteries, rather than as a screening test for people with no symptoms of heart disease -- the benefits far outweigh the risk of the radiation, according to Einstein and Hausleiter.

CNN: Heart test can pack radioactive wallop

She blocked a man's legal battle to see a test-tube baby daughter, who was conceived after his relationship with the mother broke up.

BBC: NEWS | UK | Profile: Elizabeth Butler-Sloss

One early test will be a government proposal to limit electoral spending, blocked by the opposition.

ECONOMIST: Politics in Chile

It took over half an hour for David Silva to test Buffon in the Italy goal and after Luca Toni had a dangerous header blocked at the other, Silva shot just wide with a second attempt.

CNN: Spain beat Italy in Euro penalty shoot out