New rules on community CSGO servers now make it that plugins that offer players the ability to use skins and or weapons/ranks they don't actually have will be banned. What this means is that CSGO plugins websites such as https://forums.alliedmods.net will no longer approve plugins that do this and have already started removing well known popular plugins that are used in most Surf/Bhop servers. Any server operators who ignore these rules who already have the plugins will be disabled. This means your server will not show up in the browser anymore for anyone.
You can see one of the plugins here.
This is the official email archive
Vitaliy Genkin has made a big mistake with this.
Source: http://www.reddit.com/r/GlobalOffens..._server_rules/
tl;dr basically valve is banning servers that allow players to use skins they don't own