There seems to be a descrepancy between my webazlier stats and the adsense impressions for a website of mine. Is it possbily for users to block adsense ads showing ??
You can't block AdSense but you can disable Javascript. But, majority of computers have Javascript enabled so the logical explanation would be that Google stats are wrong. Personally, I don't use their tools for statistics, they provide inaccurate data for who knows what criteria. I recommend using other methods for tracking visitors, impressions, etc. If over a prolonged period of time you still keep getting less impressions on adsense but website visitors remains the same, then check your adsense block may it's targeted for a certain region, in result not counting the results from other regions.
Highly possible.. There are several ad blockers available, like ABP for Firefox and some Internet Security Tools.
Yes it is possible for your users to block adsense ads, and I've yet to read about a good method to not show your content to such users.
I also get this a lot. There can be a huge difference between page view statistics from adsense and AW stats. Blocking Adsense is a piece of cake, you don't even need any fancy software for it. Unfortunately it hurts the webmasters. I was a member of hundreds of forums and the other day I checked on about ten of them (Most of these forums were relatively new when I joined them) Six of the ten forums were no longer online, probably because the webmaster could not make enough to cover the hosting costs.