The biggest dongle of them all: the internet
Saas is a form of copy protection. It's a dongle. Adobe is using it. Salesforce. Facebook. Even Hacker News. So please, let's not pretend that software is defective when its copy protected. The difference between a business that uses some form of copy protection and one that does not is measured in millions of dollars. I asked a question about this a while ago and got crickets so allow me to rephrase.
You use copy protected software every single day of your life so you surely have an opinion on what works and what does not. I have a program that will run on a server near a Postgresql database. It's a mobile and web-enabled developer tool similar to pgadmin3. What would be best practice for copy protection? The best we've come up with is a phone home scheme. We'd like it to be as transparent to the user as possible.
There's a great big whopping difference between the Adobe example and Facebook. One of them (facebook) the product is the network. It is inherently uncopyable. The other (Adobe) the "network" is bodged on to try to extract just the "uncopyable" attribute without providing any value and, in fact, causing a great deal of value to be lost by invalidating many use cases of the product (archival, offline, etc).
Its not about copy protection vs not, its about how much of your customers' resources and goodwill you are prepared to burn and how much value you are prepared to subtract from your product in order add that "uncopyable" attribute.
Copy protection isn't free. If you choose it, its likely to end up being your most expensive feature to add and support while simultaneously making your product less valuable to your customers.