It depends, if someone is convicted of a crime I'm pretty much ok with seizing assets acquired from the crime. Lets say a sports car was purchased with drug money. Take the car, sell it, and use the money to pay the costs of the law enforcement or heaven forbid restitution to the victims. That doesn't mean their legal defense (aka party) funds.
What I have a real problem with is when they seize money & property based solely on suspicion and the people have to prove their innocence.
Taking the assets of someone (life, liberty, or property) of someone duly convicted of a crime and falling within the penalties for that crime is one thing, and constitutional.
Unfortunately, with civil asset forfeiture, the object itself is the criminal, just by its presence. It isn't even a question of proving individual innocence, it is a question of having your assets taken and you
not even being charged with a crime--the asset is claimed to be there because it is supposedly the product of criminal activity. If you seem like someone who is going to squawk, the crime part is easy enough for the unscrupulous to arrange. ('Oh, look at the little baggie we 'found' under the seat!'--easy to palm for the camera, and 'discover', after the dog sits down, of course--something mine will do on a hand signal, no word spoken, and easy enough to do obscured form the cameras.)
That denies the person being robbed of a platform to prove innocence and forces them to sue to get their assets back, or provides leverage in the event of complaint to take the vehicle, too (and all in it) while the accused faces felony drug charges.
The whole system just begs for organized corruption, and the eventual result will look like the
Montana Vigilantes, only they only had one jurisdiction to cover. That would prompt a Federal response, and similar from LEOs who were not 'dirty', because of the way it would be portrayed and end up in a street war between police and the populace--one of the reasons dirty cops are seen as the lowest of the low and integrity is supposed to be paramount.
Ripping the Constitutional foundations of the Due Process requirement from underneath that thin blue line at any level--Federal 5th Amendment protections, 4th Amendment protections and at the State level 14th Amendment protections against the loss of life, liberty, or property without Due Process, by making the very actions Due Process is supposed to protect against part of that Due Process is wholly contrary to the spirit of those unalienable rights to Life, Liberty and the Pursuit of Happiness.
As for proving innocence, when the burden of proof of guilt should reside on the State, if there are no criminal charges made, there is no innocence to prove. If the level of robbery is kept low enough (below a few thousand at a pop), there cannot be an economically viable recovery without some sort of award for damages, damages which would also have to be proven in court, unless someone can find good representation pro bono. We have the best justice system money can buy, and usually, you get what you pay for, so the odds of that are far too slim unless there is a name attorney out there hunting for a case to build reputation on.
What Sessions has proposed is expanding the legalized and unconstitutional theft of property by LEOs who are so inclined, effectively sanctioning the largest group of armed highwaymen on the planet, anyone behind a badge.
While I will be the first to state that not all police, police or sheriff's departments, or even Federal LEOs will engage in such activity, it will take only a handful of such to completely alienate the Law Enforcement community from the people, and the level of enmity will go up, fostered where there was none, elevated where there was--a level that has been approaching limited warfare in some places already. I see this as a foolish move on Sessions part, unless he is trying to encourage corruption in law enforcement and blood in the streets.