Here are examples:
Direct, in person, action to stop a pirate board that had thousands of my images in 2009.
http://wp-board.com/ (at the time it was as large as KK is now).
The images linked below have names blacked-out because most settlement agreements have a non-disclosure clause.
This image shows a screen cap taken today of a folder on my system. Its exactly 100 WORD files (see lower left) and each document is a settlement between $250 and $1000 from just one group of guys on that one website. Settlements above $1000 or that required monthly payments were handled by lawyers so the documents are not on my system.
http://wp-board.com/gfy/word-files.png
There was 4 settlements of $20,000 or more (each) from that one website. One guy had to pay me and 3 others ($25,000 total). 
http://wp-board.com/gfy/beard.png
If you take action (not just whining) you can limit copyright infringement. Not eliminate, but limit. And any limiting of infringement of your materials very likely means increased sales of your content.
I used to run a non-nude multi-model website and it was being hurt by 
http://wp-board.com/ back in the spring on 2009. Within 60 days of shutting down that piracy my sales went up 28% (documented) and many of those subscribers were returning subscribers - meaning they had been members recurring but stopped when they could get free it from at WP. Soon as the free content was stopped they came back and paid. 
No - That one website is not just a rare case. You can discover and stop pirates on many, many sites if you try hard enough.
Motherless.com - One guy posting my stuff there lives in a $500,000 house and did it as a hobby. He hired a law firm that was familiar with copyright law and they advised him to settle. He paid the firm, the firm transferred money to my lawyer, and here is the check to me (October 2012):
http://wp-board.com/gfy/logan.png
Non-Nude.tv had many domain names over the years and is now out of business. But, guys posting there... oh sure. Have a case in Federal court now against one, have settled with maybe 15 others, including this guy (July 2013):
http://wp-board.com/gfy/hirsh.png
By the way - that guy owned a $1,000,000+ property in Connecticut and hired a law firm that specializes in copyright law. 
http://delioandpeterson.com/
Think they would have had him settle for that amount if he could have been found not guilty in a trial?