> It was reasonable to arrest people who actually broke into the base and those who organized it. Going after those speaking in support is what's excessive

Speaking out, yes. Helping organize? No.

Where the UK took it over the top was in using terrorist statute to shut down the organisation. That was unnecessary. But if the organisation helped organise the action—and this is not yet proven—its assets should have been frozen while the organisation and its leaders are investigated. If the organisation were found to have knowingly aided and abetted the break-in, it should have been shut down.

All of this could have been done using mostly civil and a little criminal law. None of it required terrorism laws.