Did the guy who said he was going to "destroy America" have a public twitter feed? I'm wondering if making your tweets protected is enough to keep the FBI from reading them.
I think you are underestimating the reach of the FBI and DHS.
They know EXACTLY whose IP address is posting every comment, they just never go through them unless your spouse's body turns up somewhere. Then they go through everything.
What is surprising to me is that they went through the e-communications of these two simply because they were traveling to the US. That's new info to me...I didn't think they did that.
I'm not sure you understand the question. It's not a matter of IP addresses. Protected tweets are not publicly accessible, so it's not a given that intelligence agencies have access to them unless Twitter is providing it to them, or they've hacked into them.
Twitter's privacy policy doesn't actually require a warrant to give up your "private" info (including your protected tweets).
Law and Harm: We may preserve or disclose your information if we believe that it is reasonably necessary to comply with a law, regulation or legal request; to protect the safety of any person; to address fraud, security or technical issues; or to protect Twitter's rights or property.
I doubt Twitter gives them everything since it's a difficult engineering problem to handle that much data. But I could easily believe the FBI has a list of terms or phrases that Twitter self-monitors for.
When I go through their publicly available profile and look at their tweets, I can see tweets that did not appear in my timeline as public replies usually do. I can only assume these are DM's.
EDIT: Am I somehow mistaken? I've seen them not only on well-known people but on friends as well when I asked them about this.
If you follow me and I @-reply someone who you do not follow then that tweet will appear in my public timeline but it will not appear in your home view.
I've followed both and have seen them in their individual profiles which is why I always chose to use SMS for things that weren't meant to be public. Any public @reply or retweet I should see and have seen. If these are DM's I shouldn't see any part of the conversation.
You may be right but why am I seeing @gruber's (as an example) replies to devs or bloggers when I'm either following both or not. Keep in mind that I've almost never used the site. I've used the Twitter app for Mac or the iOS version.
The only time I don't see these comments is in my timeline. It may be that it's not supposed to happen but, from what I've seen of these posts, they weren't meant as DMs. When I read them it seemed as something more personal and less comical that exists in a normal Twitter feed from these posters.