We believe this gives that player an unfair advantage against others at their table. A player with access to such a database can call up detailed information about their opponents without ever playing against those opponents themselves. For example, there are people building databases with profiles of many players online, and they are sharing access to these databases. In between those two extremes are many tools - some of which we consider to be too close to cheating. At the other end of the spectrum, they can use a tool that informs them exactly what action to take in real-time. Both of these techniques are clearly appropriate. For instance, they can play a lot and gain experience, or they can read a book about poker. There are many things that a player can do to improve their chances in a poker game. However, we think that some go beyond what we consider acceptable as an aid to playing online. We think it is okay for players to use some of these tools and services.
As online poker has grown in popularity, people have developed tools and web-based services to help them play better online.