Gee, you amaze me, I use a handle "PinochetMustDie" and you require further information! It not just socialists it happens to, you can be really quite moderate, "a good citizen" and it can happen to you.
Take a peek at Amnesty Internationals stuff for the nitty gritty. A sizable chunk of A.I.s cases are unionists. If you are a socialist you get it worse, especially if you are effective at what you are doing. We most certainly do get rounded up.
Depending on how arrogant the authorities are effects how far they go. I live in Australia, rather a sleepy hollow and quite anti-intellectual. You would think that the cops would ignore us as not being much of a threat. They don't.
Violence against Protesters.
You may remember a school called Richmond Secondary Colledge, a passive protest occurred there over it being closed and it was the only co-ed school in the area. The communist bogeyman was raised again and again.
We attempted to frustrate the contractors work there. We were a thorn in the side of the Government attempting to show how tough it was and that resistance is useless.
The Government sent in Cops and beat up the people on the picket line. After the beatings the Police/Government wanted to give credence to their argument that we were violent and therefore the beatings were appropriate. So they arrested 8 people. All 8 were subsequently found not guilty.
Australian authorities routinely take advantage of mass arrests to gather information. The prisoners will be interrogated about many things which do not relate to the "crime" rather to their associates etc. What this information is used for depends on its nature. Who are the prominant activists. Their whereabouts, associations etc. Sometimes it is purely to intimidate. A man I knew, Ted Bull, was one of the original union militants that turned the Australian Waterfront into the most unionised industry. When he started all the stevedores were casual. It is not uncommon to be body searched purely to distress the activist.
He was arrested by the Federal Police, the equivalent to the FBI. He was beaten up for around half an hour while the pigs demanded his name and address. Eventually one said "Well let me show you what we know about you!" and "...they pulled out a file this thick on me." It was a tape on an interview with him I heard so I have no idea how thick the file was. Anyway they knew considerably more than his name and address, the last bit was to scare him.
Selective Enforcement of the Law.
Depending on the nature of the struggle/campaign etc depends on the opportunities the cops have. Industrial Disputes sometimes involve "Company Goons" - thugs. Their job is to break strikes with violence.
The cops do nothing to defend the unionists. When the unionist defend themselves the cops intervene arresting the unionsts for assault etc. Sometimes unionists will be caught away from the picket and lynched. Another unionist will be charged with the attack.
In South Africa, activists were murdered by police and army. South Africa was not the only country where this sort of thing happens. Do some research on the "Truth and Reconciliation Commision". It is because the murders that necklaceing of police informers was originally carried out. Necklacing political rivals only came later.
I don't think I can make things any plainer, unfortunately as this is typed, I cant speak real slowly.