The appearance of the Freeminer confederacy in Tau space considered by the IMG and the Colonials as their own would normally be welcomed as influx of new citizens. Unfortunately, the dubious diplomatic relations to call it delicately leave the Colonial Government with little options but outlawing the group. Based upon the information the group itself provided, it seems they have some sort of agreement with the Maltese making them inviolable to their armed forces.
That group itself also stated, that for several reasons they consider the Colonials as their enemies. Let's now have a look at those:
Firstly, keeping the Taus free. Define free. The Shogunate recognizes the Taus as free space already thanks to Colonial sacrifices on the battlefield while the Bretonians are either holding the line at Leeds or fighting for survival in the Harris pocket.
Secondly, Ruining the Taus. I believe our mutual relation with the Gaian eco-extremists speak for themselves.
Thirdly, The religious belief in peace. I'll ask you where your God is whenever you see an IMG crew floating out of a depressurized miner pierced by Supernova hits from Outcast bombers. Ours... is a war for survival. We didn't chose to fight it, but are forced to pay a sacrifice of blood every day to keep the Taus from becoming Outcast space. Slavery, piracy, drugs, abuse... Does Buddha prefer that?
Peace is a precious and a desirable thing. Our generation, bloodied in wars, certainly deserves peace. But peace, like almost all things of this world, has its price, a high but a measurable one. We in the Taus, Colonials and Independent Miners alike do not know the concept of peace at any price. There is only one thing in the lives of men, nations and countries that is without price. That thing is honor!
Since they are civilians however, they will be given time to reconsider where they operate and with whom and how they wish to live. In short - they WILL be outlawed the moment they conduct the first transgression against either the Colonial or IMG interests.