For your consideration ...
But that still begs the question, how do DEA agents know who's carrying big money?
But if they can just take everyone's cash, why wouldn't they go after everyone, even the small fry like me? $100 is $100, and you get it for maybe 2 seconds of work.
I am going to suggest that the people who had their cash "confiscated" are on the radar for some reason.
As the declared the winner, I feel it my responsibility to assist you in your search for answers, once again. Answered in the order you posted .....
1.) DEA agents, (absent any prior knowledge of a person under investigation or as a suspect), know because they are tipped off. Either by agents at airports working the security checkpoints, or by undercover DEA agents working the TSA security checkpoint lines. Or, by going over the Customs Declaration Form OMB NO.1651-0009 that have been filled out by passengers that are leaving, or coming into, the United States, via international fights. Coming into the the US, regardless of nationality, these forms are filled out and collected by airline staff about an hour in advance of the aircraft landing. Everyone goes through customs and immigration both ways on an international trip.
The question on the Customs Declaration Form OMB NO.1651-0009.
The statement concerning money on the form.
Even the US Government states on the form itself that all carrying any amount of money, is legal.
2.) Can you imagine the outcry if a DEA agent, or the police, started confiscating small amounts of money from people just because? Agent/Police: This $100-$200-$300 you are carrying is highly suspect. Why are you carrying around this much money? Only drug users, and drug dealers, carry this much. We are going to relive you of this and take it. Yes, even though you haven't committed a crime, nor do we think you committed a crime, or are going to commit a crime, and that we really can't articulate any valid suspicions or possible motives for you having this money, but we think you are guilty of something drug related. Since we don't believe your explanation why you have this money, (wink-wink inside their heads), but just in case, because we, (assume), think there is probable cause, it's ours now. Pretty sure if this happened it would be considered outright armed robbery and theft by any government agent. Just as it is considered outright theft when larger amounts are taken absent any actual evidence of criminal activity.
3.) You would be incorrect, that those that have had their monies confiscated "are on the radar for some reason." These armed DEA agents, and armed police on the highways, are just fishing. Searching for law abiding people to mess with, and profit from the theft. It is only when they find someone with a large amount of cash, that they are then on the radar. When before such interaction, those DEA agents hadn't a clue.
Here is what the term is: Civil Asset Forfeiture. In the United States, law enforcement agencies have the authority to seize cash and other assets
suspected of being connected to criminal activity,
even if no criminal charges are filed against the owner.
On highways and roads, police may, do, seize cash from motorists during traffic stops, often in areas with high drug trafficking activity. Of course though, every area in the US can be declared areas with high drug trafficking activity. Every highway and road can be considered a trafficking corridor. Because illegal drugs, and those transporting them, are really everywhere. So in the DEA and police criminal thug mind, everyone is suspect and fair game to steal people's money.
Now, you may ask. What is the monetary threshold that armed agents might confiscate, (aka commit armed robbery), from lawful citizens just because they want to under the guise of suspecting?
A 2020 study found that the median cash forfeiture in 21 states that track such data was $1,300.
And the reason is greed. That's why it is actually armed robbery. The Department of Justice’s Equitable Sharing Program allows federal agencies to collaborate with state and local police, enabling local agencies to recover up to 80% of seized assets, regardless of state laws limiting the percentage of seized assets they can keep.
I hope this helps you to understand how far too many innocent people get caught up in this type of dragnet. Besides, the vast majority of bad guys, high level and low level that deal in the drug/narcotic trade, are already on the radar at some point. It's just that government agents always always always take the path of least resistance. And taking money from innocent people is a path of least resistance.