
Crowd Source the Truth is a small group of online citizen journalists and investigators headed by George Webb and Jason Goodman. Today they did a livestream to You Tube and reported on a possible dirty bomb attack in Charlestown set up by the Awan brothers.
Geroger Webb reveals this information at around 49:20mins on the live stream and continues to elaborate on it for another 1hr 30mins. He explains that he called the United States Coast Guard and told them about the possible dirty bomb aboard the Mersk Memphis. He goes on to say the coast guard were "hesitant to call out all the dogs and radiation meters without knowing who are sources are.” Webb explains his sources “exist within the Midwest,” were “American patriots saving our country from terror attacks”. Goodman and his team then started to track a cargo ship called the Maersk Memphis that was heading to Wando port terminal, Charleston.
Clear and Present Danger (Calm Before the Storm?) maerskmemphis


Obviously putting stuff like this out on the internet can be very dangerous especially if there is no proof to back any of it up. Within minutes this information was posted to Reddit and 4chan/pol.
A nuclear event will occur on an eastern seaboard port within weeks - 4chan/pol - 06/15/2017

After reports from various concerned citizens I guess they had to do something so they put up a safety zone around the ship r a couple hours after the initial report and started updating people via Twitter.

Here is an update video by Crowd Source the Truth where Webb goes into further detail about his phone call with the coast guard and his sources.
Maersk Memphis Update: US Coast Guard / DHS Sweep for Radioactive Material
USCG Statement


Is George Webb the person that has been arrested?
At time of writing George Webb hasn't posted on any of his social media accounts today. Also weirdly Jason Goodman currently has a live stream on You Tube but hasn't mentioned George Webb yet.