The Yiddishe Boycott

To boycott is a form of response that displays strength, and the symbolic and spiritual counterpart is as much if not more important.

An individual once asked the Rebbe what his stance should be regarding acquiring German-made products in light of Halacha and Minhag?

The Rebbe responded:

“Surely, this is more a matter of feeling rather than a question of Jewish law and custom. Consequently, as in all matters of sentiment, it is difficult to express an opinion that would have universal application. At any rate, it certainly cannot be categorized as a "weakness." On the contrary, a decision of this kind bespeaks strength of will, all the more so since it entails some inconvenience. Nor can it be considered an "impropriety" since it is based on a principle which may be considered to come under the category of "Remember what Amalek did unto you." … Moreover, I do not think that anyone seriously believes that the Germany of today is entirely different from the Germany of two decades ago.”
The Rebbe then continued, stressing the more critical issue at hand: just as there can be a physical “final solution” —the physical extermination of six million Jews h”yd— so too there can be its spiritual counterpart —mass assimilation— which we battle with today.

In the Rebbe’s words:

“Each and every one of us who is aware of the situation must do everything possible to counteract the tide of assimilation by positive and dedicated action, to strengthen the eternal Jewish values and Torah-true institutions in his community and environment.”

See the original letter here