Influencers don´t often show that their advertisements were paid

Many partnerships are often not classified as advertisement. Many challenges are made for example without the community even knowing that these were paid for. They may think that this was an brilliant idea from the influencer himself. Trying to hide it is a bit sneaky. The public may be misinformed by that.
People who find it out may interact with the advertising company differently because actions with companys relay on trust.
Ads have to be transparent.

Social media platforms

Entire social media platforms are designed for mostly one group: The influencers, not the consumers.
For example Instagrams new IGTV: Creators are the new media! Many people don´t want to wait for a special TV show, so they create their own platform.

One one knows what is reality and what is not

There are people that post content and pretend that a brand paid for it when they didn’t. There a rules in many countries that advertisement needs to be tagged. That is often done with hashtags like #ad #advertisement #sponsored. When having post that are ads and posts with ads and both of them are not tagged as an sponsored post the line between those two disappears and no one knows if there are ads or not. Gouverments have especially problems with tracking that and violations won´t be discovered.

Sources: https://medium.com/crobox/under-the-influence-the-power-of-social-media-influencers-5192571083c3
http://theblogabroad.com/2018/06/24/influencer-marketing-101/