Original: However, anonymous open proxies increase the user's anonymity or security when browsing the web or using other Internet services: a user's true IP address can be used to help deduce information about that user as part of an attempted computer crack.
Simplified: Anonymous open proxies will also make the user more anonymous and secure when browsing the web or using other internet services: a user's true IP address can be used by a hacker to get information from the user's computer.