Question: I asked [how I can resize the browser window with JavaScript](https://stackoverflow.com/questions/7022787/can-i-resize-the-browser-window-size). Everybody told me not to do it. Why is this a bad practice?

I think sometimes it can be good. For example, I want to show users a tweeting popup page. After a user tweeted, I want to redirect him to twitter main page to let him verify his tweet. But tweeting page is small and main page should be big. In this case, making the browser window bigger seems good for user. Am I wrong? Then how should I do in this case?

**Update**

I think I need to make somethings clear.

1. I also don't want my browser to be resized. Resizing users' browser is usually bad. What I want to know is that there could be some case it can be good.
2. I also don't like popups. But as @zzzBov said, pop-outs are different. That is used in many websites even in Stack Exchange(You can see share buttons under the favorite button). I don't think it would be better if those buttons were jQuery modal dialog.

And, JavaScript `resizeTo` function can resize the browser. When I tested that function, it works well in browsers but Chrome. In Chrome, it works just in popups. I might be wrong, but I guess Chrome team also may thought that the `resizeTo` function would be needed in popups.

**Update2**

Most people just don't want the method `resizeTo` to be used anytime and anywhere. I think if that method were totally evil and useless, the browsers vendors had already disabled that method, but they didn't. 

In Chrome and Opera, the `resizeTo` method is available just in popups, and in Firefox users can disable it manually. I'm sure that one should be very careful when using the method. But I believe this method can be useful in some case.

Answer: 
Don't move my cheese!

I have my windows expertly arranged on my multiple widescreen monitors, so I have a few non-maximise browsers (to avoid wasted space from some sites at the side). The last thing I want to happen is for you to resize my browser and all of its tabs to a size that you feel is appropriate.

Other less web-saavy consumers of your website may be spooked by it doing it I guess, and could possibly keep the window that size forever (as they may be unaware of how to change the size).
Personally, if you resize the browser or do anything that gets in my way I will close your page and banlist it on my firewall to make sure I never come across it again, not even by mistake.

"In this case, making the browser window bigger seems good for user." <- Anything that "seems good for the user" is inherently wrong. Let the user choose what's best for them.