There are two main reasons why it makes absolute sense to care about license compliance.

A) You are obliged to, it is illegal not to care.

Meanwhile, it has become more than standard to use components and services provided as open source. But everything – even software – that has been created is protected by creators and intellectual property rights.

The fact that something is available, does not immediately imply that everybody is allowed to use it for every purpose. Assume you left your mobile phone in a coffee shop. This would not immediately imply that everybody seeing it lying around should feel invited to make a call.

So the creator of an open source component may or may not want you to use the software. To express his ambitions, he is obliged to create a so-called license. The license clearly defines what is allowed  and what is not. INTERNATIONALLY HARMONIZED LAW DEFINES THAT THIS GRANT HAS TO BE EXPLICIT. There are no implications! If a grant is not explicitly stated, like “The creator grants everybody the right to use, modify and distribute this software…,” you are not allowed to use, modify or distribute it!

If you do, you are doing something illegal. That’s the same as if you stole something. And hopefully, you would agree that you would not want to steal.

B) You may not want to bear the risk of not getting it done.

Many licenses grant you the rights only conditionally:

“… provided that the following conditions are met:..”

Depending on the license, the effect of not being compliant could revoke the grant. Some licenses allow you a period of 30 or 60 days to get back into compliance. Others immediately enforce compliance.

Depending on what you are planning to do with the software, this might cause more or less trouble. Having a huge distributed base, e.g., navigation system in a car, the effort of exchanging the software back into a compliant status is almost impossible.