That's why this is an investigation looking for evidence and not a conviction.
This is how it works, at least in civil law countries. If the prosecutor has reasonable suspicious that a crime is taking place they send the so-called "judiciary police" to gather evidence. If they find none (or they're inconclusive etc...) the charges are dropped, otherwise they ask the court to go to trial.
On some occasions I take on judiciary police duties for animal welfare. Just last week I participated in a raid. We were not there to arrest anyone, just to gather evidence so the prosecutor could decide whether to press charges and go to trial.
Note that the raid itself is a punishment. It's normal for them to seize all electronic devices. How is X France supposed to do any business without any electronic devices? And even when charges are dropped, the devices are never returned.
This is how it works, at least in civil law countries. If the prosecutor has reasonable suspicious that a crime is taking place they send the so-called "judiciary police" to gather evidence. If they find none (or they're inconclusive etc...) the charges are dropped, otherwise they ask the court to go to trial.
On some occasions I take on judiciary police duties for animal welfare. Just last week I participated in a raid. We were not there to arrest anyone, just to gather evidence so the prosecutor could decide whether to press charges and go to trial.