Non specific wording when reporting. First you have to define the word "Protest"
A protest more often means someone ringing or writing or just saying I protest this or that.
When individuals ring or right to their government centre or member it can be seen as a protest.
Define the word protest:
protest noun
noun: protest; plural noun: protests
ˈprəʊtɛst/
1.
a statement or action expressing disapproval of or objection to something.
"the British team lodged an official protest"
So in a country with a population of 1,357,000.000 people then 500 people writing to the government centre and protesting this or that in a day is almost nothing, well something but with a lot of zeros on the right hand side of the decimal point.
I would say that US government bodies would receive more than that every day just about the gun crime, gun laws, NRA and so on.