The scam itself is based on the type of light given out by the laser pointer, the way power is measured, changes made to the laser pointer and ignorant and/or dishonest sellers.

Type of light

These lasers are advertised as green lasers and should give out green light and only green light. That how ever is not the case. Virtually all supposedly high power green laser pointers on ebay emit a combination of green light with a wave length 532nm light and infrared light with wavelengths of 808nm and 1064nm light.

All genuine high power green laser pointers have a built in filter that prevents them from emitting infrared light. The laser pointers on eBay are missing these filters which have either been removed or deliberately manufactured with out. Removing the infrared filter from a laser pointer increases its power and makes it a lot more dangerous.

Take a 240mW laser pointer commonly found on eBay as an example. This laser pointer is likely to have only 40mW of green light with the remaining 200mW of light being infrared light. Customers pay for laser pointers with 240nm of green light and only get laser pointers with 40mW of light. Effectively cheating them of 84% of their money.

The other problem with missing infrared filters is the lasers are very dangerous. Infrared light spreads out like a torch beam compared to green light which is in a narrow beam. Green light being visible can be avoided but the Infrared light because it is invisible cannot be avoided. Most safety glasses that protect against green light are completely transparent to infrared light. This means a person wearing safety glasses and using one of these lasers is less likely to avoid the beam and much more likely to suffer damage to their eyes.

Measurement of power

The power of most laser pointers will peak in the first few seconds then stabilize at a level much lower than the peak. Reputable sellers will give the average power as the advertised power. Ebay sellers on the other hand use the peak power as the advertised power. This is very deceptive because it misleads people into thinking the laser is much more powerful than it really is.

Modifications

These laser pointers are only designed to handle powers from around 5mW to 10mW. The sellers modify the laser pointers by increasing the power from the batteries to the laser diode so the diode emits a more powerful laser beam. The problem with this that the diode is not built to handle the higher power and will have a much shorter life cycle and is likely to burn out. Many ebay lasers lose power or burn out completely in a matter of hours or even minutes. The lens in the laser pointer the acrylic coatings are also not designed for the increased power and are likely to damaged with reduced performance or fail completely.

These eBay sellers are not laser experts and generally have little or no understanding of the laser pointers they sell. This means they are not able to give qualified advice or recommendations and the level of support and service they can provide is minimal. Their general response to customers when there are problems with laser pointers is to ship it back for a replacement. Given that the cost of the laser is not much more then the cost of shipping it, most customers cut their losses at that point.

Possible remedies

Laser pointers with powers over 5mW are classified as hazardous goods and are not allowed on eBay. If you have been scammed by one of these sellers, you can threaten to report them to eBay and they may have their account suspended or even closed.

If you paid with PayPal, you can also open a dispute for goods not as described. The dispute may not be decided in your favor but most sellers are willing at that stage to issue you a refund. If you paid with a credit card, you can start a charge back with your credit card company in a similar manner with a greater chance of success than PayPal.

The last option is to bluff. Claim that you will contact eBay, the police and the government department in charge of consumer affairs in their country if they do not issue you with a refund. Considering they are selling an item prohibited by eBay and illegal to sell (legal to possess) in a number of countries, this bluff is very effective.