Google and the entertainment industry have long had a complex relationship. After years of taking heat from the MPPA and RIAA, the search giant is desperately trying to shed its reputation as an accomplice to copyright infringement.

Why? Well, avoiding billion dollar lawsuits like the one Viacom filed (unsuccessfully) a few years ago would be nice. But Google also wants to be on good terms with the music and movie industries so it can strike content deals that will help products like YouTube, Google Music and Google TV to thrive. The company still gets the majority of its revenue from search ads, a reality it knows won’t last forever.

The changes started off small but are now getting more serious as content becomes a more important focus for Google’s business. Still, even after some of the most significant changes, the record industry and Hollywood tend to fire back complaining that they don’t go far enough. That happened again this week when the RIAA put out a report questioning the effectiveness of Google’s search results tweaks.

As our own Brian Proffitt demonstrated with some test searches, the RIAA might have a point. But Google is trying. It has a delicate balance to strike between the interests of copyright holders and the users who generate more than a trillion search queries every year. It’s eager to please the content industry, but has to roll these changes out gradually to avoid a mass user freakout.

So how has Google altered its search engine and other products to cater to big copyright? Here are four notable recent examples:

1. Blacklisting Terms From Autocomplete and Google Instant

In January 2011, Google started blocking certain terms from its Autocomplete and Google Instant features. Rather than undertaking the full-blown search results censorship the entertainment industry wanted, Google decided to meet them half way and at least stop recommending piracy-related search terms to people.

Since then, the list of forbidden terms has grown. Even Megaupload is still blocked from Autocomplete, even though that site was seized by the U.S. government over a year ago.

Overall results are mixed. If I type “hurt locker torrent” into the search bar, it doesn’t show me instant search results (nor did it attempt to autocomplete the phrase). But “torrent hurt locker” is another story. That returns links to torrents for the popular movie, followed by an article about how the film’s makers sued thousands of BitTorrent users. Careful!

2. Streamlining The Copyright Takedown Process (SometimesTo A Questionable Degree)

When you run a user-generated content site as massive as YouTube, you have to be capable of handing potentially millions of copyright complaints. To keep up with the never-ending flood of complaints, Google has progressively made it easier to file them. Its Content ID feature lets copyright owners supply YouTube with audio or video reference files that the system then uses to automatically identify infringing content and flag it for further action.

As you can imagine, Content ID has resulted in some highly questionable takedown requests. So last year Google implemented an appeal process to help minimize frivolous takedowns. Of course, even with protections in place, eyebrow-raising takedown requests are still granted from time to time.

Google also now claims to be responding to copyright takedown notices within 24 hours, a promise it made to the content industry a few years ago.

3. Tweaking Actual Search Results To Discourage Piracy

The content industry has long wanted Google to not just tweak search suggestions, but to actually remove and downplay results that lead to infringing content. For years, Mountain View was unwilling to tinker with the secret algorithm that bulldozes billions of dollars into the company every year. As big content companies become more valuable potential allies, Google has warmed up to the idea.

Google is constantly bombarded with requests to removed URLs from its search results on copyright grounds. In 2012, the company pulled 50 million infringing links from its index. In the last few months, the number of requests have skyrocketed, so it’s likely we’ll see even more links de-indexed in 2013.

Granting DMCA takedown requests is one thing. What the content industry has wanted all along was a deeper, algorithmic change to Google’s search results. In August, they got their wish.

In its most radical anti-piracy move yet, Google added copyright takedown requests to the more than 200 signals it uses to rank and index search results. That is, if a site gets a high number of “valid copyright removal notices,” it may wind up taking an SEO hit as a result. Not surprisingly, the RIAA was quick to cry “not good enough!” only six months after the admittedly measured changes were made.

4. Next Up: Defunding Piracy Sites

To quell any remaining doubts that it’s serious about piracy, Google is about to cave into another long-held entertainment industry wish. According to the Telegraph, Google is currently in talks with MasterCard, Visa and PayPal to cut off funding to sites that engage in copyright infringement. The report is short on details, but presumably such a tactic would be reserved for some of the worst offenders, especially those who dodge takedown requests or operate in other jurisdictions. This is an unconfirmed report, and one that reveals only discussions, not action. If Google does proceed with this one, it’s anybody’s guess what the timeline might look like.

Of the changes that have been implemented, each one is decidedly measured. Google can’t quite afford to go nuclear with its antipiracy efforts, much to the chagrin of the industry. This is going to be an evolutionary and thoroughly imperfect process. As the business incentives and industry pressures mount, expect to see Google make increasingly aggressive moves. And, like clockwork, expect the RIAA’s complaints to keep coming.