1. Background
- The story involves Impulse 45 WE trains, popular in Poland, managed by a local operator Koleje Dolnośląskie.
- Eleven trains bought about seven years ago began needing maintenance after reaching about one million kilometers.
- An independent workshop won the servicing tender over the manufacturer due to lower costs.
- After servicing, trains would not start despite no error messages; brakes released but no movement occurred.
- The workshop struggled for months and contacted manufacturer, which blamed the workshop.
- Finally, the workshop hired Polish hackers, including Michał Kowalczyk and team, to analyze the software problems under a tight 3-month deadline.

2. Technical Investigation
- Focused on power inverters and Programmable Logic Controllers (PLCs) which control motor functions.
- PLCs run specialized firmware on tricore CPUs, programmed via graphical block diagrams, no source code available.
- Firmware extracted via undocumented debugging protocol with default credentials.
- Multiple versions of firmware existed on different trains.
- Firmware analysis uncovered hidden functionality locking trains after servicing by unauthorized workshops.
- Found hard-coded geographical coordinates of competitor workshops embedded in software.
- Locking triggered by:
- Time since last authorized service (initially 10 days, later 21).
- Serial number mismatches of replaced components.
- Odometer verification inconsistencies.
- Geolocation-based locking in competitor workshop areas.
- Special date-based lock/unlock cycles.
- A secret undocumented button combination on driver panel resets locks, indicating intentional sabotage.

3. Outcomes and Reactions
- The hackers managed to unlock the trains hours before contract cancellation deadline.
- Manufacturer denied knowledge of locking code, later sued the hackers for copyright infringement.
- Public exposure followed, including media coverage and parliament meetings.
- Manufacturer accused independent workshops of poor quality and claimed exclusive servicing rights despite contract terms.
- Workshop directors revealed similar cases where they paid manufacturer fees for train unlocking without explanation.
- Legal investigations launched by prosecutor, anti-monopoly office, and anti-corruption bureau.
- Manufacturer filed multiple lawsuits including defamation against MP supporting the case.
- Court proceedings ongoing, slow and complex due to technical nature of evidence.
- Trains continue to be locked following servicing in competitor workshops, problem remains unresolved.

4. Key Actionable Items & Tasks
- Continued legal defense in multiple court cases related to copyright and defamation.
- Ongoing expert analysis of firmware dumps to prove existence and function of locking software.
- Monitoring for new incidents of train lockups after servicing.
- Raising public and official awareness to pressure regulatory intervention.
- Encouraging transparency and accountability from train manufacturer and maintenance policies.
- Investigation and regulation of manufacturer’s servicing monopoly claims.
- Outreach to and protection of independent workshops servicing these trains.