By and large there is no stealth in space. You can take extreme steps and dodge the many sensors and AIs that labor to catalogue anything bigger than a couple of molecules in an orbit. But it never works for long. Even Borsten's Leap with a substandard port facility would usually get hours of warning about any ship thrusting for it.
They could track the numerous Belter ships, record their engine emissions and then after a mining trip compare those engine emissions to the previous ones to determine how much more mass they had in a hold for tax purposes. Not that they found a way to tax the Belters. Belters had nukes and the port officials had zilch beyond their own sphere of influence. The last expedition against the belters was a subject of tavern jokes.
A major problem was smuggling, and it was done in a very overt fashion. Since the Leap was situated ideally between two pockets of commerce ships were already passing through rather than taking the 'long' way around. It was the goal of the Borstenim to stop everyone of those ships and wring a few credits from them. It was the goal of the merchant captains to avoid this process if they could.
Usually a ship would break out of hyper with zero velocity relative to Borsten, get vital news updates, refuel and take a smoke or the equivalent. There was some hunting for cargo because you were usually stopped and fined for some nonsense safety inspection. The victimless crime sector of commerce got to work on the crew and after a few days you left, bellies full, having had a smoke or whatever and little lighter in the wallet.
The lighter wallets of crew and officers did not bother the captains that much. It was the delays. When the banks had paper on your ride, time was money. An ordinary trader held loans amounting to 11,000 credits per day. So even one day's delay was a sizable loss amounting to several senior crew members' monthly salaries. Add to that fines, fees and the intangible opportunities lost because a captain didn't act in time or missed a deadline with a hit shipment. The Borstenim did not finance ships of their own, and they just didn't get it.
Captains could get external drop tanks and merely jump in and then jump immediately after getting their bearings and news updates. The Borstenim hated this and put their patrol cruiser to work stopping ships and running the inspection scam on them.
The captains found a new trick. Tanks strapped on they boosted for their jump point. No flip over, no deceleration. They hit the jump point at high speed. Once in the Borstein system they kept accelerating, falling through the gravity well of the planet beyond the ability of the patrols to intercept.
They did need their news downloads: gossip about all the little wars going on, what stocks were up to, what to buy low and sell high, and where. The Borstenim were adamant about refusing info dumps to these ships practicing the equivalent of the ancient practice of cutting across a gas station to avoid a corner traffic light.
That fact there was no stealth in space did little to console Brockhurst B. Borsten the Third, planetary governor, proprietor, and de facto owner of most of the commerce on Borsten's Leap. He was a prime example of someone who let their money work for themselves. It was widely accepted that was a lucky thing for him since he couldn't make a milli-cred on his own. All B3 knew was he had a ship too and it was a big one and it should do something about this.
B3 stormed and fumed to the captain of his patrol cruiser. The patrol captain patiently explained at length that his ship only had finite propellant reserves and finite acceleration. Those trader monkeys had done the math and they couldn't be caught before blipping to the tachyon spawning ground.
B3 blustered and ordered the patrol to do everything they could.
Fire warning shots? Warning shots were pretty stupid in space (this was cleaned up from what the patrol captain called it). You didn't see a laser unless it in fact hit you in a vacuum. That wasn't much of a warning. Missiles would either hit a ship or miss it and any navigator could tell the difference.
Fire real shots? Actually firing on ships could be considered an act of war, not just by their planets of origin but ... the Bank. You didn't declare war on the Bank. Besides traders would take the long way around the Leap at that point.
Sow mines so they'd have to slow down? Then no one would pass through for reals. The place would become a sargasso in a year.
The Borstenim parliament had a brief respite when B3 went on a fact finding exchange to Inerze and Zaonia. They even held out hope he'd piss off the feudal and honor obsessed Tech Knights of Zao and get bumped off. In the meantime the Borstenim trusted in B3's short attention span and simply began charging for info dumps to ships passing through. The charges included a hefty fee for presenting a hazard to navigation, breaking the speed limit and refusal to accept a safety inspection.
Most captains paid it electronically and for a while that was it. Still cheaper than stopping off. Let their crews take long showers and bitch.
Then a new faction appeared. People began sending free info dumps to passing ships. The messengers were the strangest of life forms, the altruistic. They didn't care about money. They liked messing with the government or were pro trader or they hated B3. Didn't matter. The point was ships were still whizzing by and Borsten's Leap wasn't able to charge them!
Info dumps were sent by social media or mail or piggy backed on fund transfers. Even B3 wouldn't screw with those. He used those! This resulted in the same suggestions as before (remember the short attention span?)
Then he threatened to stop payment on all funds to the patrol. The patrol captain was upset by that because truly burning a world down to the rock was easier than getting the uber-rich to cough it up after stiffing you. It was time to think out of the cruiser. The captain proposed a very simple plan because there was no time to make up a complex one. He did establish that he didn't get his rank due to the pleasing symmetry of his features. Strictly off the record he presented his plan and the Borstenim acted on it.
Ships passing through still got all manner of social media, electronic mail and fund transfers with info dumps. Only now some of the dumps were from the Borsten government hired hackers. The viruses they contained were mostly harmless. Their effect on the ship's computers were minimal. They could be contained and wiped out without a second thought. But you gave everything a second thought when you were about to enter hyperspace.
Cue soundless braking of a number of merchant ships. Cue several patrol ships and shuttles soundlessly revving their engines. All you could hear were the ka-chings as ships were hailed, boarded and inspected. They all failed. Their brain boxes were tainted by a virus! Fortunately the Borstenim had antivirus software for a nominal charge. After you paid the hefty fcost of a safety inspection. In fact the info dumps had extensive accurate and up to the minute updates of flagged messages with malware included in their official info dumps.
Rumor was, for an increased cost you could purchase antivirus software that would be good against all present and future viruses for a year. They were, of course, completely true.