if you were to spend time in the spam sections for an hour a day and reported all the garbage posts, you'd hit 5000 reports pretty easily.
Imposible an hour can reported hit 5000. it's not easy, because reporting have wait time each.
example : for senior member have wait time 4 second, full member 8 second, etc...
for other country have slow internet, have much time loading for hit 5k reported/hour.
It is impossible for a single day, but it is possible if you spend an hour per day to report spams with average rate of 100 spam reports per day; you will have 5000 spam reports after 2 months. Sometimes, I saw threads in which I can see 10 or 20 spam posts; it is easy.