Well I’m not so sure that is a reasonable expectation (certainly visiting a website isn’t the same as an attorney client communication), but either way the 4th amendment only applies to searches and seizures by the government not 3rd party websites.

I fully believe it to be a reasonable expectation which is unfortunately violated daily and routinely often under the nefarious guise of marketing.

Well as I previously mentioned the 4th amendment only protects from unreasonable searches and seizures by the government...reasonable belief or not the 4th amendment isn’t going to protect you from data collected by non-government actors (unless the government directed them to collect it for them).

It's unfortunate that the U.S. has such lack privacy protections compared to Europe.

And it starts with expectations, which our government belittles us for having.