Just the current search, but the problem is millions of pages run third-party ads, and most are run by very few networks. These ad networks can aggregate the terms and then they have previous searches as well.

Doesn't Incognito browsing, like present in Chrome, remedy all these worries?

People find ways around it, for example for a while Flash didn't respect incognito so ad networks just used their cookies instead (I think at one point html5 storage was being used too, but could be wrong).

There's been various HN posts about how people circumvent browser privacy settings to track you across websites and even tricks such as generating an almost unique key by hashing together browser, fonts installed, IP address, etc.. I'm not sure of the current state of play in that war though.

I guess if you really don't want people to track private searches with your accounts, use a whole other browser where you're not logged into Google in incognito mode.

not if you are logged in using your google account

Pedophilia is illegal in most countries, I'd be happy if ad networks gather data about your interest on young boys and pass it to the feds! Beasts!

Edit: judging by the downvotes, I guess a good bunch of hackers like to live in atrocity!

I think the downvotes are because you're missing the point so hard that they're assuming you must be trolling.

He who would trade liberty for some temporary security, deserves neither liberty nor security (via Ben Franklin)

You got the oft-excluded part of the quote right -- temporary security -- but the actual quote is, "he who would trade Essential Liberty for some Temporary Security, deserves neither Liberty or Security."

Many people omit the word, "temporary". The suspicious part of me says they do it so their (mis-quoted) statement appears more bold and uncompromising.

When you click a link, you usually send the refferrer url to the site you go to. Naturally google's search terms are a very easy to parse and a well known url. So when you click a site's link they know that you came from google and that you searched for xyz.

Duck duck go actually redirects you in a way so that the referrer is not known to the site. They all think you came from duckduckgo.com. DDG also keeps no logs. Basically your own activity online cannot be used against you.

Now, privacy aside, I really like DDG for other reasons, like search relevance, continuous scrolling, zero-click info, etc. So its kind of win-win for me.