The verb doesn't follow the had + past participle rule because it's not acting as a regular verb. It's called a modal verb. https://learningenglish.voanews.com/a/everyday-grammar-you-had-better-learn-modals/2865365.html

Grammatically correct: In this place there are many people with whom I can speak. Colloquially, we say: In this place there are many people who I can speak with. Technically, it should be "whom", especially with the original sentence structure. However, we usually just say "who" in every day speech, but please note that when doing so, the structure of the sentence changes and "with" comes at the end. With whom are you going? (correct) Who are you going with? (grammatically incorrect, but sounds natural, very common) With who are you going? (incorrect and sounds weird. no one ever says it this way) Whom are you going with? (arguably grammatically correct, sounds OK... uncommon) By not separating the placement of the "with" and "who" in the sentence, it makes it very apparent that "who" is wrong in the phrase "with who". (Hope this isn't too confusing of an explanation.)

PROTEST is a noun. This entire headline is a phrase without a verb. All the words are actually nouns in this phrase. All the nouns are modifying other nouns. Furniture modifies factory, and pay (wage) modifies cut (reduction), and furniture factory modifies pay cut, and pay cut modifies protest.