youtube - death to intellectual property?

I haven't spent much time on youtube in the last several years but recently, I was kind of amazed to see how many clips from my films (DVDs) are posted by other people.  Not only do they post the clips but they run ADs before them?  So potentially, these cats are generating revenue off of my work.   numbers like... 77,009 views and  52,000views - if all those people stepped up and bought a DVD or rented the film digitally, we could go make more films.

I suppose people are excited to share things they like but is there absolutely no realization that what they are doing is illegal and actually takes away revenue from the filmmakers?  

Part of me says, cool, share away- hopefully it promotes the work on some level.  Another part of me says, what a minute, that's chicken shit- I spent time and money creating that content and why should you get to give it away.  I don't really want to start policing the internet for piracy.  I know it obviously happens, I just wish people would think a little more about the consequences of what they are doing.  aka @someGuyNamedDave   sorry about the rant.  #ScratchingMyHead