乱感悟:为什么无线网要加密

自从有 WLAN 这东西以来,似乎只要是自己搭建的无线局域网,就一定要加密。之前在国内的时候,这个问题似乎有很明确的答案:为了防止蹭网。而现在在英国,学校免费提供的已经是 50 Mbps 的无线网络,而一年付 £ 116 的话就可以达到 150 Mbps 之快。除非我需要全速下载大量大文件,否则仅仅是看看视频、上网的话,如此高的带宽根本是用不完的。而至于局域网的 ARP 攻击之类,哪里都可能发生,真的有黑客的话怎么也防不住。那么为什么无线还是要加密呢?

我好奇地搜索了一下“ WiFi no password risks ”,果然已经有人问过这个问题了。其中一个解答(链接)让我豁然开朗:

Those who say it isn't dangerous don't know much. Having your Wifi open will cause others to use your connection slowing your speed (happened to me). Also, someone with experience can invade your computer using your network and take information off of your pc. They can also leave behind some viruses or anything of the sort.  

Another reason is if someone else gets a virus it can transfer through your network and on to you.  

Now the biggest reason to block it is, you don't know what others are doing. They can be using the internet illegally (Fraud, hacking, child Po**, mp3 downloads etc.). By them using your connection they use their ip address and when the feds come looking they will be after you and not them. 

Please put a password ASAP. Only let those you trust access the wifi. Can't stress this enough.

其中最重要的部分我已经加粗了。的确,就算你不被攻击,同时用你的网络的人也可能做出任何一件事:欺诈、黑客行为、儿童色情、非法音乐等等。而在执法机关看来,这是你的网络,他们只会来抓你而不是免费蹭网的人。这种免费帮人背黑锅的可能是存在的,因此即便有造福社会的伟大胸怀,也不该冒此大险。