1. But few people can maintain that level of vigilance for very long.

2. But he also warned that the threat of another extremist attack remained very real and vigilance was needed.

3. We are also asking that everyone be on a state of heightened vigilance, he said.

4. So you need to have a higher level of vigilance when reading email, especially ones that contain links to streaming video.

5. The first was a high level of vigilance on server logs and tracing back over what had changed in its infrastructure.

6. But in Germany, with its strong stance on data vigilance and privacy rights, consumer advocates are more reserved.

7. Remember, constant vigilance is the price of free email.

8. Signs urging vigilance in health and safety cover nearly every wall.

9. Our travel advice advises particular vigilance during Ramadan, when tensions could be heightened.