Which one of the following self-made sentences sounds more natural:
> - They are under the surveillance of the intelligence agency.
> - They are under the Intelligence Agency’s watchful eyes.

Do these two expressions have different meanings or they ca be used interchangeably?
Based on dictionary definition about [surveillance][1] I guess it would be better to use the former sentence, although both mean the same and both are formal.


  [1]: https://www.vocabulary.com/dictionary/surveillance