So, if I'm walking down the street, doing nothing illegal, and a cop decides to stop me for questioning, all they have to do is say I looked suspicious? Or does he need to back up that assessment with a fact or two?
Lets look at your question this way.
A) You are robbing houses and a concerned citizen sees you robbing houses.
The police are called and when they arrive, you are all done robbing houses and are walking back to your van full of loot, at the time they arrive you are doing nothing illegal. All you're doing is walking back to your van.
Yet you fit the description of the person that was suspiciously removing items from a home where you don't live.
Do the police have the right to question you?
B) you are moving things out of your friends house because they had to work but today is the last day for them to get their stuff out. (They're moving)
A concerned citizen thinks you are robbing a house and calls the police.
The police arrive and you are walking back to the van full of your friends stuff. At the time they arrive you are doing nothing illegal.
All you're doing is walking back to your van.
Yet you fit the description of the person that was suspiciously removing items from a home where you don't live.
Do the police have a right to question you?
The point here is that police officers are employed to deter crime, investigate suspicious activity, keep the peace, report and investigate crimes and violations of laws.
I don't believe a police officer responding to a 911 call of suspicious behavior is a violation of your rights.
In the case in question, a man with a firearm is video taping or taking pictures of a federal building at night.
Something about it seemed strange to a civilian and they called 911 to report it.
The police officers responded to the call and ascertained that the person involved was not committing any crime nor did he intend to commit a crime there that night.
They let him go peacefully after that.
I am a firm believer in the constitution and the rights of American citizens.
I do not believe that as Americans we should be oppressed by a tyrannical government at any level.
I do however believe that we should be careful not to declaw and detooth our guard dog, lest he be unable to assist us in our moment of need.