[EDIT]
The sirens are going off as part of Severe Weather Awareness Week

"6:55 PM:  Another simulated tornado warning will be issued for participating counties in Minnesota. Those counties are: Anoka, Beltrami, Benton, Big Stone, Carver, Chippewa, Chisago, Clearwater, Cottonwood, Crow Wing, Dakota, Douglas, Freeborn, Goodhue, Grant, Hennepin, Hubbard, Isanti, Jackson, Kandiyohi, Lac Qui Parle, Lake of the Woods, Le Sueur, Lyon, Mahnomen, Martin, Mc Leod, Meeker, Mille Lacs, Morrison, Mower, Murray, Nicollet, Nobles, Norman, Olmsted, Pine, Pipestone, Polk, Pope, Ramsey, Red Lake, Redwood, Renville, Rice, Roseau, Scott, Sherburne, Stearns, Steele, Stevens, Swift, Todd, Traverse, Wabasha, Wadena, Waseca, Washington, Watonwan, Wilkin, and Wright."

http://www.crh.noaa.gov/mpx/?n=swaw

[END EDIT]

Erm anyone know why the tornado sirens are going off in Coon Rapids...

Rickrolling is the latest internet meme. Simply put someone will post a link purporting to be something interesting and relevant to the subject at hand but it will in fact be a link to 'Never Gonna Give You Up' by Rick Astley on youtube. If you clicked the link then you have been 'rickrolled'.

I have to admit I have been rickrolled more than once, and it does make me smile.

Rick Astley himself thinks it is all a little amusing too, "“It’s a bit spooky, innit?” said Rick Astley, the singer who made the song famous in 1987 and who is not dead". You can read (and listen) more in the LA Times blog about his thoughts on the subject.

Or for more information on this and other internet memes check out the wikipedia page.

You may also find the following information relevant.