Sequental access issue

[Tauseef A]

hi guys , in n-tier there is sequental access from UI--> BLL --> DAL. but when we user linq can we say that UI can access the data source directly , it ot doext not voilate the convention ? or i am wrong some where . because we can do like that in UI Customer cus = Datacontext.gettableTauseef A Khan MCP Dotnet framework 2.0.