MySQL Detecting cheaters
You can use this query:

SELECT dataEntryIP FROM app_log
GROUP BY dataEntryIP
HAVING COUNT(*) &gt; 1


Be careful above query doesn't use any index.

If your table will be grow, index the dataEntryIP column

ALTER TABLE `app_log`
ADD INDEX `dataEntryIP` (`dataEntryIP`);




Update 1

Oh sorry I did not understand your question.

I suggest before you insert the data into app_log remove www. prefix to unify domains (www.domain1.com is equal to domain1.com).

But for now I think it can help:

SELECT dataEntryIP from (
SELECT replace(domain, 'www.', '') as domain_without_www ,dataEntryIP from 
app_log
GROUP BY domain_without_www,dataEntryIP ) t1
GROUP BY dataEntryIP 
HAVING COUNT(*) &gt; 1


But It is very slow, if your table is big. 

if you can remove www. before insert to table, your query will be easier and faster.