As a sizeable hoster of things and collector of links, Google receives its fair share of Digital Millennium Copyright Act (DMCA) takedown notices. Only, that fair share has increased by around a billion per cent since 2006. Under the DMCA signed by Bill Clinton in 1998, sites like Google aren't liable for material they host, provided they respond to a valid complaint from a copyright holder in a "timely fashion". It's a sensible, well-intentioned piece of law that lets sites that rely on user-submitted content (YouTube, for example) exist.
But it's also worryingly susceptible to abuse -- big copyright holders know how the system works, and sites are liable to assume guilty until proven innocent, since they don't want to be part of any lawsuit.
Unfortunately, an increasing number of copyright holders are learning that DMCA spamming works. They use bots to trawl hosting sites and search engines, find anything that looks remotely infringing and then order Google to take it down.
The numbers in Google's latest transparency report, noted by TorrentFreak, bear out the strategy. Google is handling 75,000,000 DMCA requests every month for search alone. That's an astronomical increase from the hundreds of thousands per month it was handling in 2011, and a different order of magnitude to the eight per month from the early 2000s.
On the one hand, you could interpret the numbers and assume that DMCA is working as intended, ridding the internet of its offending copyrighted material. Or, you could assume that millions of valid links are getting caught in the crossfire, and you can't even post a video of a dancing baby without getting DMCA-spammed these days. I guess it's up to you (and a federal court) to decide.