Find Text Validation Rule - passes on hidden text

Unexpectedly, the validation "passed" on text that was hidden in the meta data and not displayed on the web page.

Is this the way it was designed to work or is this a defect that needs to be reported to Microsoft ?

If this is the way it was designed to work - shouldn't there be some indicator as to what level you are using the Find Text command (i.e. on hidden text, displayed text , or for both ?)

Note: this has also been posted in the VSTS General section