Do you have any evidence that proves a correlation you are suggesting or should we just take your word for it?
I speak dutch and I know a lot about Europe because I aim a European, I know that people yelling Hamas in Europe are never non-muslims.
This is one of the demonstrations in holland, where a dutch MP (socialist) and the 99% of the demonstrators are muslims because they feel more connected with Gaza and are therefor more motivated to protest on the streets. Native Europeans also disapproved the actions of the Israelis but they also all see Hamas as criminals (that(Hamas) is why the vast majority of Europeans are reluctant to support the palestinians, because they feel they would be siding with Hamas if they would protest), that is why the politician in the video of the netherlands below was "attacked" (figuratively) by his political opponents, his party and in the press. He was asked to resign by the opposition, because he protested with people who were yelling "Hamas hamas jews on the gas" (in dutch: Hamas, Hamas Joden aan het gas)
the Netherlands:
[ame=http://www.youtube.com/watch?v=PLlHPPO25nM]YouTube - 090103 pro hamas intifada hezbollah expressions during anti israel demonstration[/ame]
Germany:
[ame=http://www.youtube.com/watch?v=5MYtuR5yssQ&feature=related]YouTube - Demonstration gegen Israel in Bremen am 03.01.2009[/ame]
London:
[ame=http://www.youtube.com/watch?v=qinvlROaWbg]YouTube - Protest in London against Gaza offensive - 10 January 2009[/ame]
Mostly the protests are also organized by muslim organizations, you can check that on the websites of these muslim organizations.
I m not saying that there were 0 European natives there, but 99% of them were muslims. The protests themselves are all requested by muslim organizations in Europe. You will see some socialist politicians marching in there because they feel that they have to show solidarity in order to win votes.
You can check this by looking into the European muslim organization websites or the local government website where the protest was announced with the organization that organized it.
Europeans are disgusted by words like "Hamas, hamas jews on the gas", because their are still a lot of survivors of the holocaust who still live in Europe (Both victims and perpetrators).