You basically hashed over the same things you and I have both already said. I'll make it a little clearer.
Differences:
#1-Drugs are less likely to be carelessly left behind because they cost money. Drugs cost money, and you don't leave money at someone's house very often, do you? Files would of course be left.
#2-Illegal files are not only free, they are non-portable. Even if someone emails or copies the file, the original stays on the computer unless deleted. Drugs are portable and would be expected to go with the person. Files=not.
#3-Everyone is capable of searching the house for drugs. Everyone is not capable of searching their computer.
#4-Drug users are generally easy to spot. Computer file sharers are not so easy. The dark socks worn with shorts may give some of them away, but too many of them look like normal people. ;)
#5-Considering #3 and #4, everyone can be expected to know when someone using drugs has been in their house and should be expected to look for illegal objects, and could reasonably be expected to find them. Everyone could not reasonably be expected to find illegal files.
#6-Everyone found with illegal drugs is not always even suspected of being in possession of those drugs. I've got family in law enforcement and I majored in criminal justice, with quite a lot of contact with those in the force. The gal with the drugs in her car who says the boyfriend did it usually has to show signs of being a drug user or have a large amount of the stuff to get arrested. If they are in her purse, then she knew about them. It's rare for someone to go in a woman's purse without her knowing about it, and even rarer that she would not check her purse and easily see the drugs within a half hour of being out somewhere.
The decision on who to arrest and prosecute is based on the circumstances. If the cops come to your house looking for illegal files, and you've got your shorts and black socks on, I'd recommend getting a good lawyer. If you are a regular Joe or a youngish kid, or especially a (non-horribly-ugly) woman, get the lawyer anyway, but I doubt it will make it to trial.
There are just too many differences in these cases for any competent lawyer to allow most of their clients to get convicted for something like this.
Do you really believe those gals that say their boyfriend put the pot in their purse? You believe they didn't know about it? To get off for something like that, you need a very good and airtight explanation of how something illegal came to be in your possession. If you could prove that your house had been broken in to the week before the cops busted you with a few joints under the couch, AND your house was messy so you can prove you don't clean very often, a good lawyer would make a case that the burglars left their pot behind. You'll have to have a VERY good explanation for why there was pot under the couch. Most people don't, because it was their pot.
Unless they were intentionally left there. Maybe someone was worried about getting popped after leaving your house and think that either they will have a chance to retieve it later or left it there and forgot to grab it before they left. People who are high do the damnedest things that offen defy logic.
#3-Everyone is capable of searching the house for drugs. Everyone is not capable of searching their computer.
You might be able to convice a jury of that, but it will cost you a few grand in legal fees.
The decision on who to arrest and prosecute is based on the circumstances. If the cops come to your house looking for illegal files, and you've got your shorts and black socks on, I'd recommend getting a good lawyer. If you are a regular Joe or a youngish kid, or especially a (non-horribly-ugly) woman, get the lawyer anyway, but I doubt it will make it to trial.
And if you are lucky enough to have a judge, DA or RIAA lawyer looking to make an example of someone, you had better have a reincarnation of Raymond Burr on retainer because the jury will be your last hope. And if you have a judge, DA and/or RIAA lawyer who are of the same mindset, there's a pretty good chance that you will not be allowed to show the jury any evidence that would clear yourself. And a lot depends on what kind of court you end up in. In "criminal" court you have an even chance of being able to use constitutional protections. But if you are in civil court, due process is more easily avoided...again, especially if the judge is sympathetic to the RIAA's point of view. When these groups and individuals are looking to make an example of someone the last thing you want is their complete and undivided attention.
If you have considerable assests or just something that would make a nice trophy for some hack, I wouldn't take a day of your life on a dare.
Do you really believe those gals that say their boyfriend put the pot in their purse? You believe they didn't know about it?
I've known some gals who are "straight-through-the-skull blondes" who (1)are vapid enough to not know and (2)are not attractive enough to get out of it.