You should be and for very good reason.
The tag line on that poster, "We get the job done." is nothing more then the unvarnished truth as Canadian Soldiers, Sailors and Aircrews have proved over and over again during rather short history.
It was Canadian Militiamen that stemmed the tide of the American advance into Upper Canada during the War of 1812
During the Boer War, Canadians broke through Boer lines and defenses that stymied the British Army.
In WWI, not only did Canadians take the German strong hold at Vimy Ridge, after repeated failed attempts by both the British and French, but it was Canadians of the PPCLI that held the line while the French forces were in retreat and stopped and repulsed the German attack following the first use of Gas.
During the Second World War, Canadians fought in every theater of that conflict, in the air, on the ground and at sea. It was units of the RCN, RCNR and RCNVR's that saved the US coastal shipping from the U-Boats second Happy Time. Had they not done so, shipping from the Gulf of Mexico and up the Eastern US Coast would of come to a grinding halt. In Italy, it was Canadian along with Poles that cleared the way for the liberation of Rome, but instead of being allowed the honour of taking that city, they were called back at the last minute to allow US troops to liberate Rome. During D-Day, Canadian had their own beach and were the only allied force not only to make their first day objectives, but exceed them even though they were facing some of Hitlers best Panzer units. After D-Day, it fell to the Canadians to clear the Channel Ports from Normandy up to Holland. Without these ports, the Western Allied advance would of slowed down to a crawl due to an extended logistics train, and would allowed the German Army to consolidate and dig in stronger defenses.
Canadians were there in Korea and have served with honour and distinction in many lands and battlefields since. When it was time for the first contingent of Canadian troops to return to Canada from Afghanistan, the US General Commanding requested that they be immediately replaced by another Canadian force, stating that if given a choice between having another US Division or a Canadian Brigade, he would prefer to have the Brigade. A few years back Time Magazine (If I am not mistaken) conducted an interview with a number of ex-Talaban Commanders. When asked which troops they feared, they stated "Canadians, they kill everything and fight with a fierceness that rivaled their own."
But the poster does make a valid point, Canada's Military is woefully undermanned, ill-equipped and poorly funded. This is nothing new to Canadian Military Personnel, it's been that way ever since the Lord Strathacona Horse were tearing up the South African Veld during the Boer War.
No matter which Political party is in power, the Canadian Military is and most likely always will be treated like an unwanted Red Haired Step-Child. And yet, given the lack of manpower, old and worn out equipment, and being poorly funded, the Canadian Army and Navy and Air Force get the job done, often in a cheaper, quicker and cleaner way then the militaries that boast of larger numbers, higher tech and deeper pockets.
So yeah, you better be scared of us, coz another thing Canadian Troops are well known for, and that is not taking any crap from either allies or foes.