Google, Facebook, TikTok and others are starting to talk more about how their algorithms work in a bid to win trust.

Yes, but: It's hard to know what isn't being revealed.

• Google on Monday published a blog post that shows users how to access more information about their search results, the day ahead of its Q4 earnings report.
• Facebook similarly released a post last week about how its News Feed algorithm works the day before its Q4 earnings.
• TikTok last year, amid the threat of a ban from the Trump administration, walked Axios and other reporters through an extensive presentation of how its prized algorithm works.

Be smart: While these efforts to be transparent are helpful, they don't usually provide the full picture about how the platforms' algorithms work, in part because they don't want their systems to be gamed by bad actors.

• But without full visibility into how content and goods are distributed on the internet, it's hard for consumers or regulators to trust that Big Tech companies, most of which are publicly traded, are using their power for good.

The big picture: Around the world, regulators are beginning to question whether the algorithms used to drive billions of dollars of internet commerce and content are biased towards certain demographics, philosophies or viewpoints.

• While new research shows that political bias is not likely to be driving most of these companies when they engineer algorithms, experts worry that tech giants program their machines to favor profit over societal benefit.
• New research from the University of Washington, for example, alleges that Amazon's algorithms promote vaccine misinformation.

Between the lines: Republicans and Democrats have both cited transparency into content moderation as a goal of changes to Section 230 of the Communications Decency Act.

• The Platform Accountability and Consumer Transparency Act introduced last year by Sens. Brian Schatz (D-Hawaii) and John Thune (R-S.D.) would require online platforms to explain content moderation decisions to users.
• Congressional Democrats last week alleged that algorithms from social networks like YouTube, Facebook and Twitter may be radicalizing people.

What to watch: Competition regulators around the world are starting to dive into whether and how Big Tech algorithms harm consumers or competitors.

• Early drafts of a new Australian law require tech giants to give news companies nearly a month's notice before making any content-related algorithm changes.
• The U.K.'s competition authority put out a report last week detailing ways algorithms can reduce competition.