It would be no surprise that record & movie companies would have whole departments dedicated to searching out pirating.
That's their business, to sell their product, they're huge companies for the most part and take their profit margin very seriously.
What I think is ridiculous is when they squawk about a 2 minute clip of something being posted on youtube.
That's when it must be automated searchbots doing their job. I've posted minor segments of things on youtube, and because I got those clips straight from a DVD or blu-ray instead of capturing it off the TV directly, there is some coding there to allow those searchbots to see it.
But the same clip I have may have been posted by several other people, they just didn't get it off a DVD, so theirs are left alone.