Here's a quick question, how did Secret Service know police officers in DeKalb county, GA checked Obama's background?
They're watching everybody.

You've a computer science major right? My best guess would be Server access logs! They record what resources are requested (Obama's file) and the IP of the police onboard computer.
It isn't so much the technical side I care about as much as why are Secret Service concerned with someone checking Obama's background? Are they concerned about something in his background that they don't want public?
Mind, I'm not defending police making random background checks on people, but it seems a little odd for Secret Service to be involved in this. We pay them to protect the President, not to hide his past.
Sorry, I misunderstood 
In that case, good point it seems very strange that 2 officers of the law are punished for doing a little digging. Like you say What have they got to hide?
No need to apologize, it really wasn't clear from my comments. To be honest, even if the server logs did hold that information (and I fully expect they would), how did the Secret Service know to go check the logs? I suspect there is some sort of flag on Obama's name that notified them, which again leads to the question, why?
Tough one to comment on.
The Police shouldn't be doing background checks on ANYBODY without cause or reason
However Obama is a public official so its a bit extreme.
There have been many attempts to get at Obamas birth, college, Ayers relationship and passport documentation .... surprisingly the transparent president has sealed all of these. It is just not his 'birth' certificate that people want to see. Is there any controversy here ... is there something to hide. The president who is for transparency and honesty who keeps up the policy of 'questionable' wire taps and allows the govt to watch and listen to phone lines doesn't want people to know his business.
I'm sure certain people will point out that GW never showed some of his 'military' records and that why wasn't America concerned then. The fact of the matter America was concerned then - it did not matter. Meet the New Boss - Same as the Old Boss. Time for a change .. Boulderdash.
You are forgetting that one of Bush's first acts as president was to seal presidential records going back beyond his father's all the way back to some of the Reagan stuff.
And while it is disappointing that Obama isn't being as transparent as promised, we still have the issue of a lot of criticism for doing what Bush did from people who never had a problem with it as long as it was Bush doing it. Obama doing the same thing drives them crazy. Kinda double standard.
This doesn't get Obama off the hook for being like Bush, but this kind of thing prevents me from taking the criticism too seriously.
Maude_Lynne