Outside of running AdAware on desktops to remove spyware, I have never seen a problem across a couple of networks I manage that can't be simply detected and removed as data miners etc by AdAware.
I write up very strict user policies, NO online email services are alowed at all (hotmail, MSN etc) NO chat software whatsoever is allowed to be installed, nosurfing unless to customer or work related sites. Computer at people's homes are for that junk, not a company network.
If a few things are picked up, very rarely, I just remote in to the desktops and do an inventory of installed apps. If I see, MSN or W.H.Y., I remove it and notify thier employer of the policy breach. From that point it is out of my hands and up to the employer. If the employer doesn't do anything about it and ends up paying me $150.00/hr to do an onsite cleanup, it doesn't take too many invoices before they start acting upon your notifications.
if the employee is bummed, they have the rules, they broke the rules and maybe next time they will think twice before installing MSN chat on thier next employers computer.
It sounds a little harsh, but when a company invests tens or hundreds of thousands inthier network and some $20/hr employee screws it up and costs the company 150/hr, they deserve to be unemployed. There a plenty of others that will do the same job without compromising the company's investment.
So beyond that, I see no need for regulation outside of the company.
If you can't train staff and enforce policies, you shouldn't be in business in 2004.
Why should we let someone else to do something about it when we can take care of this at the company level, which differs by each company involved?