One persons terrorist is another persons freedom fighter.
The IRA, for example, was well funded through donations to give one of the most recent examples. The ANC is another one that springs to mind:
"'The ANC is a typical terrorist organisation ... Anyone who thinks it is going to run the government in South Africa is living in cloud-cuckoo land" - Margaret Thatcher, 1987
Going back a bit further, many European countries actively tried stopping recruitment to the International Brigades fighting against Franco in the Spanish civil war, up to and including imprisoning people.
Irgun is another example: A zionist military organization with several massacres to its name that was considered a terrorist organization by Britain at the time, as well as by some important contemporary Jewish organizations. Irgun is one of the direct predecessors to the Israeli Likud party, that has been part of most Israeli governments since th late 70's.
There's a long range of causes that various subsets of Western civil society have given support to that have been considered terrorist by contemporary authorities.
Some of them are still seen as terrorists in retrospect, some of them are seen as heroes and freedom fighters. Some are seen as either/both depending on who you ask.