can somebody tell me if these IPs are bots or legit website visitors

they constantly show up in top 10 IPs

[prozz]

1]
(143.182.246.21) proxy2.ch.intel.com
(143.182.246.6) proxy3.ch.intel.com
(143.182.246.27) proxy1.ch.intel.com
proxy4.ch.intel.com
it's user agent: Mozilla/3.0 (compatible)
should I block their subnet?

2]
hanta.yahoo.com
I know this one is a Yahoo URL checker or something. Does anybody know what does it exactly do?

3]
I also constantly have this kinda guys, in my top 10 hitting IPs:
12-21-84-189.mar.mn.charter.com
200-207-44-37.dsl.telesp.net.br
24-90-1-158.si.rr.com
adsl-156-59-217.asm.bellsouth.net
adsl-67-38-64-243.dsl.sfldmi.ameritech.net
asnet01-032.dallas.texas.net
asnet01-216.dallas.texas.net
cm198.86.120.24.lvcm.com
cust-isdn2-135.lasvegas.net
ip68-10-167-94.hr.hr.cox.net
lsanca1-210-086.lsanca1.dsl.gtei.net
modemcable037.94-130-66.mtl.mc.videotron.ca
nvcr01m01-11.bctel.ca
I'm pretty sure these are some email harvesting guys.
Note: These are all showing up as Mozillas, everything else I have blocked.

4]
Does anybody know of way (a script, a regex rewrite_mod) to be able to limit the number of the clicks an IP can do on my site.
eg. if IP X clicks on links more than 100 links within 1 hour, block him, or deliver a zerosized page to him.
These bots keep on clicking on (findwhat)PPC links...and create a lot overhead.

I'd really appreciate your advice on these issues guys.

[Key_Master]

1. Mozilla/3.0 (compatible) is a common user agent for some types of proxy servers.

2. Like you said, it's verifying the submited website exists and is accessible.

3. Can't offer you much there.

4. Hidden links fed to specific types of user agents via a SSI script. You can control who gets the hidden link and who doesn't (for the most part). In most cases the rouge bot will follow the link and from there you can ban the IP.

[prozz]

Hi Key_Master,
thanks for reply, I especially like idea #4 :) will experiment.
I'd probably have to create a separate exclusion list, such as top SE's robot IPs and rest should get blocked if they follow the link.

re: 2.
Is it possible it checks and sees content has changed and might remove from directory? (lets say the keywords have changed and it doesn't belong in that category anymore)
Does yahoo have a function like that?

[Key_Master]

Possibly but I doubt it's checking sites for changed content. I think Yahoo hand reviews sites that they recieve complaints on. I could be wrong though.