Until they have been served a warrant, they are not under a non-disclosure warrant. That's how the canary is legal.
> hey can compel you to lie/not comment if asked
No, no they cannot. They can prevent you from commenting, they can NOT compel you to lie.
Lying and not commenting are very, VERY different.
The Federal Government disgrees with you. Just one example:
https://www.google.com/webhp?#q=least%20untruthful%20manner%...
It has nothing to do with being compelled to lie by a court order. It has nothing to do with the Judicial system at all. It has nothing to do with lying vs. not commenting.
Until they have been served a warrant, they are not under a non-disclosure warrant. That's how the canary is legal.
> hey can compel you to lie/not comment if asked
No, no they cannot. They can prevent you from commenting, they can NOT compel you to lie.
Lying and not commenting are very, VERY different.