How to protect yourself from the new Steam Client feature?

So for example, will the game be visible to those to whom you distribute the library through Family Sharing if you make it private?

Yes.

Potato option where?

You are not the first and most likely not the last who is afraid of the new feature.
Only people could already exploit the system, the hide feature just makes it faster and easier, before you could just ask Steam support to remove a game for you, join a giveaway and then ask Steam to add it back and since that is all automated, it's done within seconds so now it just takes a few less seconds to do but that's it, so I wouldn't worry to much about it, people who want to exploit will do it anyway and sadly not much you can do about that!

Someone mentioned wishlist as an option. As you can only add games there you don't own..

Bump.
If somebody saw my first post: edited because I had couple of discussions opened and after changing tabs I responded in wrong one xD

Is there not some function of the site that keeps track of games won and prevent you from participating in future giveaways of said game? This should be done. I am also a bit unhappy about people who have the game but enter for the dlc of like a GOTY or extended version. The site could use some more functions to be sure. Also I still don't understand why anyone concerned so much about privacy wants to be on a site like this anyway. Plenty of giveaway options that don't require any level of privacy invasion or whatever people seem to think is going on.

As a variant of solution - add an option to the SG user settings to provide Steam API key, and block giveaways until the API key would be entered and checked/confirmed by SG server (I mean server-side code of the SG). With the API key those "hidden" games should be available for the SG server to check. But it requires some work on the SG code.

There already is a big topic about this, but CG, Support and thus, Steamgifts, just don't care.

Those screenshots are very very easy to edit and hide. It's been an issue in the trading community for years now.

I've had cases during my game trades where people have edited screenshots and were ready to fool me.

I really don't see a solution other than activating the game via screenshare (Discord or Teamviewer).

Anyone can edit and fake images with ease.

I'm not sure how much I care about this, but wouldn't a simpler option be to require Steamgift members to have the setting set to public? Certain groups make this a requirement. An automated search might even be created by Steamgifts, similar to games not activated.

Mods, yes I know that the status quo is to over complicate processes and then complain bout how busy you are. I'm kindly suggesting that if you support more tech friendly solutions, so many tickets and routine tasks can be improved or automated. Hopefully some of the newer mods have a more supportive mindset for some of these.

I have made a post about this, my solution would be to have the ability to set your giveaway to wishlist only, if this won't be implemented, you have to ask the winners to put the game on their wishlist,. This could work and be automated, because you can't put privated games on the wishlist, neither dlcs. https://www.steamgifts.com/discussion/BhVZ1/possible-solution-to-automatically-verify-dlc-ownership-and-privated-games