Is it bad if someone knows my IP address?
An IP address is an identifier for your computer.
Perhaps, but is it bad if they know it?
It does not matter how many anonymous posts and different accounts you use, if they have the IP address. That will tie all these accounts to the one PC you use.
So they can identify me.
You could use an IP anonymizer to help protect and hide the IP address.
I've heard that does not always work.
If you use different computers for various postings, you help confuse the data collection, though it all exists. Or you could use a VPN connection to hide your IP address.
There will still be IP address collected.
True, but the IP address will be associated with the machine through which you are connected, not your home PC.
Is it more or less important if they use the IP address or my computer name?
Someone might be able to remote in to your PC if they have the computer name. They will be able to remote in if they have your IP address.
I can change my IP address.
Yes, you can do that by changing the cmd window. It'll kill any connection you have at the moment, though, and require things to re-verify with ISP.
Makes sense. When my router changes IP addresses, I lose my internet connection.
They do it for security reasons.
Should I change my IP address for security reasons?
You could. But realize the ISP has the same files on your downloads and file history regardless of the change, and the NSA's files extend much farther to your Facebook posts and Skype chats.
So my IP address is bad to have, though I can do something about it. It is all the other stuff the feds collect that's concerning.
Wait until the IRS targeting of conservatives comes down to turning off the internet connections of those visiting politically incorrect sites. Or putting all the teen sexting pictures in a database to blackmail them if they do not vote the right way.
All Big Brother in the 1984 book threatened to do was torture you, not humiliate you, like putting those ugly baby photos on Mom's hard drive on Facebook while signed in as you.