Scope creep is always a problem.
Scope creep is evil? Maybe.
When you give on scope creep, write down the why. Read it again, a week later, and answer: was it worth it? By then, that info needs to be in your planning process.
When capture gets as easy as it should be (and remember, Capture should be easy ), you quickly have too many things captured.
Then, remember this: Delete things!
If you're capturing all the time, trust your delete-it gut. If it's important, it'll come back. The focus that comes from a reduced spread of todos will probably get you back to the item in question faster.
And don't forget that ideas are cheap, finishing is hard (and more important), and we want Less scope creep and more iterations.
A place to link to other entry-point cards.