Why put sites behind captcha verification?

One trend I have seen in some markets lately is when someone will put their sites behind a captcha.

In almost all cases it has nothing to do with geo location or geo targeting, but asks visitors to verify they are a human visitor before allowing the page to be seen.

How do search engines treat such pages or sites? Are they indexed in the same way, or does thins usually mean the pages or sites are being cloaked and different content is being shown to the visitor that what the search engines see?

Rick
Universal4

As a personal choice, I most often do not stay at a site with such, and am interested in how others feel about it.

Are you using a VPN or something when this happens? Like millions of sites, my websites go via cloudflare and that would show a challenge to anything it thought was a bot (good bots excepted), scraper or other bad actors. It should not show the challenge to good traffic, in theory. Some sites may have this protection ramped up quite aggressively. On others it might only be aggressive while they were 'under attack' from bad traffic. Surely no sites have a captcha as standard to all traffic?

I have seen such on some sites and pages while not on a public vpn.

In a few cases I tried using private vpn's that are routed only for certain enterprises, and in those cases I also tried while on my own vpn that is used only to route for a specific private lan that still exposes my home public, as well as running the same tests while not on a vpn.

Contemplating your suggestion of possibly an increase in protection due to a current or previous attack may well be one answer in many situation, thanks.

Rick
Universal4

Are you using public wifi?

I never use public wifi.

Rick
Universal4