A lot of people have probably heard, seen or experienced a boarding that had some difficulties, but that doesn't mean it's all like that.
I've been boarded probably 6 times in various places and times by both USCG and USC, but never had a problem of any kind.
As above, I think some of the times we were being watched for a long time. One time I was passing behind a cruise ship
off Cape Canaveral, and the next thing I knew they were there, never saw them coming...black go fast......
It was always done in a very professional and courteous manner.