For years they have been the silent terror of the Japanese underground train network - groping male hands whose owners make use of almost impossibly crowded conditions to fondle women commuters.
Or have they? Smarting under the announcement that subway chiefs are to introduce more women-only carriages in 2006, Japan'smale commuters are up in arms over attacks on their allegedly roving hands.
Their beef is that the new system is sexist and offers women commuters an easier ride - literally - on account of crimes many say they never commit.
"Other carriages get so crowded now. It feels like we have been punished for something we didn't do," Hisashi Yoshizawa, one male commuter, complained. "It's not right to introduce women-only carriages."
For all the anger of Japan's male commuters, transport managers in cities such as Tokyo and Osaka are unlikely to reverse the trend towards subway sex segregation.
Too many women say they have had enough of men's insinuating digits making their already stressful travel arrangements hell.
Recent surveys showed 64 per cent of women commuters said they had been groped, and a record 2201 cases were reported in Tokyo last year.
The sprawling city's 13 underground lines carry an estimated eight million passengers per day.
Japan's police take the phenomenon ever more seriously, too, patrolling carriages and brandishing fines of up to 50,000 yen (about $600).
In a radical, or perhaps just desperate, attempt to nab what they believe are around 150 hard-core gropers, officers are even turning to forensic analysis to catch their men.
Thanks to a new system perfected in Osaka, they can match tiny fibres extracted by sticky film from the palms of known suspects with the clothes of women victims.
It sounds almost impossibly complex, but the Osaka police say it helped them to convict 16 of the city's worst gropers last year.
According to Michiaki Tatsuno, of the Osaka police crime laboratory: "This step will help deter the molesters from striking."
