What can people do when they have access to someone else's wifi that's bad?

You are on your computer at home. You check your bank statement online.
I am across the street, logged into your wifi. I can see what you are looking at online. While you are looking at your bank statement, I have access to it. If you forget to log off, I will have access to it as long as I want.

In most cases the worst that happens is you’d be exposing things you share on your network, so they’d have access to any files or folders that are shared among the other computers on your network under certain circumstances.

I don’t believe anyone would have access to the information you’ve looked at online, unless it was through some sort of logging. As in they could see you went to fluther, and possibly information you’ve posted there, but anything that was encrypted would still be encrypted. And that’s only if they were looking at the web traffic directly which would take more than access to your wifi network. It would be the first step though.

Most commonly the worry is that someone will use your network to do things they wouldn’t want to do on their own. Whether that’s downloading huge files, or something more damaging. Usually there isn’t much of a threat to you. It’s just letting someone on your network can be the first step, so people generally lock that down as a first level of defense.

That’s not to say other things couldn’t be exposed, but it’s not due to the wifi network itself.

@filmfann You have to have special computer abilities for that though, no? The average Joe on a shared network doesn’t get to easily see what everyone else is doing on their computers.

If you used someone else’s wifi they would suffer a drop in speed, esp if you watch some movie or something

If you are not sharing files on your network the average person will not be able to do anything but print something on your printer. It is so easy to password protect your wifi why not do it? Unless you are intentionally sharing it with your neighbors to save money, just do it and give them the password. Almost all banking is encrypted now so it is highly unlikely your neighbors would be capable of stealing from you. If one neighbor is a bandwidth hog (always downloading movies) you can cut him off.

Download child porn and then get you arrested as pedophile.

Check also the very informative answers I got when I asked a question about the same subject.

@Lightlyseared But wouldn’t it end up on the interlopers computer?

@LuckyGuy Yes, it would end up on someone else’s computer, but you would still have to go through the hassle of dealing with the police. I read a local news story about a year ago about someone in an apartment complex who had an unprotected wifi, and he was arrested for downloading child porn. After his computer was investigated, the police did track it to his neighbor, but he still had to go through the hassle of being arrested and being investigated before he was found innocent.

If you download files illegally, the person responsible is the owner of the IP address. So, if you torrent a copy of The Dark Knight using my wifi connection, I’m the one legally liable.

Here are a couple of stories of innocent people raided by federal agents when kiddie porn fans borrowed their wifi.

Cops raid man whose Wi-Fi was used to download child porn

Wireless router hijacked for child pornography

@quiddidyquestions I was at work with a friend of mine when he pulled out his computer, and started looking at what others were doing online. I was floored. He didn’t seem to have any secret skills.

@filmfann You definitely have to have skills. Not secret skills, but specific skills.

After all is said and done, go with @amujinx‘s point.