(Reuters/Christian Hartmann)

Spotify knew it had some explaining to do. The streaming music service apologized Friday, after changes to its privacy policy raised alarms among its more privacy-conscious customers — aka, those that actually read those policies.

Spotify's latest policy asks for access to users' pictures, contacts, voice controls and location information, which sparked some concerns that the company was going to spy broadly on its users' habits. But chief executive Daniel Ek explained in a blog post why the firm asks for the things it does.

The purposes are pretty straightforward and focus on customization: Spotify wants to access your pictures to let you personalize playlists or album covers, for example. The company wants location information to see what music is trending where. Contact access would enable Spotify to let you search for friends among its users in the future. Asking for voice control permission, Ek said, also opens Spotify to offering voice controls in its app in the future.

Ek didn't say that the outcry would prompt Spotify to change its mind about what it collects, but he did say that the company would rework its policy to be a little more clear. He also promised that, while the agreement asks for blanket permission to this data,  Spotify won't automatically pick up that information from its users, or use it for other purposes:

Let me be crystal clear here: If you don’t want to share this kind of information, you don’t have to. We will ask for your express permission before accessing any of this data – and we will only use it for specific purposes that will allow you to customize your Spotify experience.

The dust-up highlights a few things. First, it shows people are actually paying more attention to privacy policies. Last week, Microsoft also got dinged by some for a provision in its Services Agreement that includes language that it reserves the right to disable counterfeit games — though not on Windows 10, as many had feared.

The backlash is also a warning to companies that it's not in their best interest to insert vague and overbroad language into their agreements. Spotify can ill afford to deal with bad consumer sentiment right now, as competition heats up in the music streaming world —and having people close their accounts in protest, as a few users have claimed to do on Twitter, is never a good thing for any service. Including more precise language and examples of how Spotify uses such data could have tamped down some concerns.

Finally, this should serve as a reminder to consumers to think about the data they're sharing in order to use services. Personally, I wouldn't mind giving Spotify access to my voice control data if it meant I could bark out an order to turn the volume down. But giving it access to my contacts is probably a step too far for me. Others may draw the line in other places. The point is that it's important to think about the data you're giving up to enable certain features, on any service, and to make sure you're comfortable with that trade-off.