Back in the 1970s there was loads of terrorist activity from groups like the IRA, PLO, Beider Meinhof, Red Brigades, FLQ, and SLA. Airport security was very tight (the laxness of the last 25 years could be viewed as an anomaly). I was strip-searched and heavily patted down on more than one occasion. Once in the Geneva airport I watched a security guard squeeze all the toothpaste out of a tube. I was never able to carry my Swiss Army knife on a plane. In the summer of 1973 I passed through airports in Tel Aviv, Beirut, Tehran and Athens, and security was unbelievable; we were constantly surrounded by soldiers with machine guns. Passengers had their cameras dismantled with screwdrivers. It was scary, but I didn't complain - I welcomed the protection. Lots of things were getting blown up that summer, including part of the Athens airport.
Nowadays we hear a lot of discussion of why the Islamic terrorists are attacking us and what we have done to cause their anger. In the '70s there was less of that sense of western blame. The stated goal of groups like the SLA and Beider Meinhof was to overthrow western democracy and bring about the revolution. Those organizations were largely made up of middle class, educated westerners - not a group that seemed particularly oppressed. Back then, even the IRA garnered very little public support, although the Irish people were widely seen to be treated very unfairly by Britain. The IRA was a band of criminal thugs who committed crimes to finance their operations, who trained with and supported other terrorist organizations, and who killed innocent civilians. Likewise, there was public sympathy for the Palestinians, but the PLO were seen as murderers rather than champions of the cause - partly because many people understood at that time that Arab governments were ensuring that the Palestinians stayed in refugee camps so they would generate an army to fight Israel.