i have installed n configured squid as ip based access control and works fine now all the systems are ip based controlled and i have few domain users( users which can be logged in from any computer irrespective whether their accout exist on that system or not) i want to put these users on user based restriction, so my question is

If i have the system is blocking few of websites (cuz ip based blocked) say 123.com for example and this domain user logs in and try to access this website i.e 123.com n in acls he's allowed to access it, will he be able to access it? cuz what i feel is although the domain user is allowed to access that site in acl's the ip will be blocking that site isnt it true?