For most people, April 20 is just another spring day. But for many a German right-wing extremist, the date bears particular significance. It was on this day in 1889 that Nazi dictator Adolf Hitler was born in the Austrian town of Braunau.

One traditional "Gasthaus" in the eastern German state of Thuringia took the contested celebrations to a new level on Wednesday, however, promoting a "birthday offer" for the Nazi dictator.

For one day only "all standard burgers and schnitzels cost just 8.88 euros", Gasthaus Goldener Löwe posted on its Facebook page. The price itself is significant to the Nationalist Socialist leader, with "88" being the abbreviation of the Nazi salute "Heil Hitler."

'Hate for the right purpose'

Despite receiving its fair share of support on the social networking site, the post was also met with considerable criticism. "Business must be doing badly if it's necessary to resort to this to get idiots to the table," one Facebook user quipped.

"Are they even allowed to do that?" asked another. Ever present on the scene in the fight against right-wing extremism was the online campaign "Hass Hilft" (Hate helps), which replied to the advert with one of their numerous campaign posters, reading "Hate for the right purpose."

"Hass Hilft" campaign poster: "Hate for the right purpose."

"Thank you Gasthaus 'Goldener Löwe'," the campaign wrote. "By means of your hate comment, you've automatically triggered a 1 euro donation to refugees and EXIT Deutschland."

'Unwilling donation'

The concept behind the campaign - launched in October 2015 by the anti-rightwing extremism organization "Rechts gegen Rechts" - is simple: for every "hate comment" reported to the initiative, one euro is donated either to "Aktion Deutschland Hilft," which provides aid after major catastrophes, or "EXIT-Deutschland," which helps people leave behind their right-wing-extremist tendencies. Since the initiative began last autumn, more than 10,000 right-wing extremists have, in turn, unwittingly donated to these causes.

The money donated to the charities is collected by "Hass Hilft" from members of the public and a number of official partners, including FC St. Pauli football club, media company Sky, and online news website "Celle Heute," which reports from the central German town, close to the site of Bergen-Belsen concentration camp, where more than 70,000 people died at the hands of the Nazi regime.

Comments influenced by historical events

On a day to day basis, around 50 hate comments are brought to the attention of "Hass Hilft." On particularly poignant days for right-wings extremists, the comment - and in turn the "unwilling" donations - can double, if not triple in number, co-founder of the initiative, Fabian Wichmann, told DW. The "hate comments" are largely influenced by the anniversaries of political events, such as today - the birthday of Adolf Hitler.

A significant increase in "hate comments" can also be fueled by particularly provocative articles about regarding current affairs - most recently the refugee crisis, Wichmann said.

What makes a hate comment?

According to "Hass Hilft, "hate comments" include those which "humiliate, denigrate or reduce human dignity, or statements which incite violence or threaten human violence."

"What we're looking for are the comments that are xenophobic, racist or homophobic," Wichmann explained. The actual or suspected membership of a right-wing extremist group is also taken into consideration. Posts such as: "I think there are too many foreigners in Germany," or "I' don't agree with the asylum policy," wouldn't been seen as hate comments, Wichmann stressed, adding that it was "important to discuss topics such as the refugee crisis."

In each case, a suspected "hate comment" is also checked for its criminal relevance. Confronted by "Hass Hilft," perpetrators have even been known to apologize for their comments.

"Some contact us, admitting that they 'went too far' or that 'alcohol played a role'," Wichmann said. "But this is still a rare occurrence."