Early on, we obsessed over this—researching every odd-looking email. Being in regulatory compliance, we had no shortage of attorneys around us, so I asked our main one about it, and to my surprise, he’s like, let them in, let them pay. Let them focus on you while you focus on their customers.

At a minimum, you can tell potential customers that they are a paying customer when asked about them (that’s the best way for them to find out, you know).

At most, you have, in some cases, paid proof and audit logs of your competitor is spying on your product. Assuming your Ts and Cs are decent, wait until they grow or raise and drop a lawsuit or threat of one in their lap. Send a copy to their suitor. That will affect their raise or acquisition.

Disclaimer: I’m not a lawyer, I just spend a lot of time talking to them.