You could be helping protect them against abuse.

Transient Workers Count Too (TWC2), a non-profit advocacy and support group for exploited migrant workers, has done a bunch of outreach programs, such as the Cuff Road Food Programme in Little India, where restaurants serve free meals to migrant workers. This week, they put out another call to action, one that should be pretty easy to help out with if you have old smartphones lying around.

The 2G network—used by many migrant workers to keep in touch with their families back home or in times of need—will no longer be available in Singapore by April 2017. Workers without 3G or better phones will struggle to call home, or even reach out to aid organizations such as Home and TWC2 when they are being exploited. TWC2's recent video series really drives home the point.

So if you're upgrading to the iPhone 7, or just happen to have a bunch of unused 3G phones lying around, click here to learn how to get them to someone who needs one.