Ghostery primary use is for both Win and Mac,.....many countless 1000s of Mac users have it installed on their browsers, it is both very useful, and removes all web addware/commericials.
Ghostery is available for Safari, Chrome, and FIrefox. Its approval rating and reviews are extremely high.
The single best FREE browswer addon for a Mac is GHOSTERY (or a likewise one called Glimmerware as recommended by Kappy)
MORE importantly it keeps hidden cookies and other junk/spam/trash from clogging up your hard drive.
It is a VERY small addon, its free, and very useful.
5 STAR rating, at close to a million users, ...and that 803,000 users is for Firefox ONLY, doesnt count Safari or Chrome
Ad Block Plus (uncheck allow some ads through to prevent Google ad trackers)
FlagFox (displays the IP and country flag of websites)
Ghostery (enable all options in preferences)
HTTPSEverywhere (from the EFF, encrypts web surfing if possible)
NoScript (a bit hard to use, drag a Temp Allow All button to Firefox's toolbar, then it's easy, just click on sites you trust only)
NoSquint (auto zoom pages to fit your screen)
TrackMeNot (drowns your real searches with random searches to prevent profiling)
Just some of the great privacy options.
You're getting some strange comments about Ghostery. It doesn't block ads; it blocks tracking cookies. It's not at all similar to GlimmerBlocker, which is not a Safari extension but an ad-blocking proxy server. Ghostery is generally safe to use, but some people have reported browser crashes that stopped when it was disabled.
Were they running old browser versions or on an older Mac? Thats the first Ive ever heard of anyone having a browser crash due to Ghostery, ....not that I doubt you at all.., I believe you. First I have heard of same.
I was a tad lazy in setting up glimmerware, it reminded me of the hassle of setting up Lil Snitch on a new machine (again, lazy). Utterly my flaw in that case, obviously.