The fact that, I don't know, Israel has been completely ignoring an UN resolution for decades, causing said terrorist group to appear on the first place? (I also have another resolution that considers Zionism as a form of apartheid) War Crimes in their last attack against Palestina? (I'll be honest: there is an addendum that says some of these crimes are being investigated in lengthy, slow and incomplete reports... but investigated nonetheless).
The blockade? Israeli citizens building settlements in Palestinian territory without being stopped by anybody even though they are illegal according to the International Court of Justice? The Palestinians have been suffering violence and hunger for decades just because some groups can't go and talk to Israel... and because some Israeli politicians think it isn't worth to sit and talk to them when, well, you have been invading their territiories (in other words: you already have all) for decades ignoring UN resolutions and nobody says a single word in the UN because the US stops any iniciatives to criticize them, much less to "cut their balls off".
This. The Israeli military and government do a lot of bad things. I hardly think I'm an evil Jew-hating anti-semite for disagreeing with their actions.
I'd also like to mention that being classified as a terrorist organization by your enemy does not make you one. "Terrorist" is just the US' catch-all term for anyone who stands up to them these days. People fighting for their homes are terrorists, software pirates are terrorists, people who disagree with the government in general are terrorists, people who would rather not be raped by the TSA at the airports are terrorists, etc. And the great thing about calling someone a terrorist is that, once you do so, no sane politician's going to stand up for that group's rights because who wants to support terrorism?