Others have commented here that this is normal, but since you're surprised about this, here's some actionable advice (as someone that's worked in very competitive spaces):

1) You should be doing the same thing. If you're not on top of the competition, they will chew you up, especially if they're better funded.

2) When you're doing your own competitive research, watch out for EULAs and ToS -- they're typically not enforceable (or very expensive to enforce), but many of them explicitly disallow this kind of thing. Use fake addresses.

3) Make sure your EULAs and ToS have similar provisions. Again, these are very difficult to enforce, but consider them as very cheap defence-in-depth.

4) Restrict your most innovative features (while they're in beta) to whitelisted user accounts. Again, not a perfect solution, but defence-in-depth.

Being a founder in a competitive space requires wartime thinking. As shitty as it is, your competitors are breaking rules and violating laws all over the place.