As an example, the following article came to my attention today: http://toronto.openfile.ca/toronto/text/byron-sonne-thin-line-between-terrorist-and-gardener
I recommend you read the entire article, but here's the part I want to call attention to, the 'laundry list' of presumably scary chemicals with dangerous-sounding names.
No one disputes that Sonne had a lab in his basement, stocked with glassware and neatly labelled containers (see photos here). There was potassium permanganate, potassium nitrate, ammonium nitrate, iron oxide and zinc oxide. There was stearine, copper sulfate, urea, hydrogen peroxide and aluminum powder, as well as dextrin, sulfamic acid, hexachloroethane, charcoal, potassium silicate and sodium bicarbonate. Sonne had plastic bags full of wax shavings and PVC shavings, and a container of hexamine tablets next to his camp stove. There was acetone, methyl hydrate and hydrochloric acid in his garage. In his furnace room, he had an electrochemical setup where he seemed to be turning potassium chloride into potassium chlorate, a shiny white crystal that is, Anderson said, a well-known ingredient in improvised explosives like TATP (triacetone triperoxide) and HMTD (hexamethylene triperoxide diamlene). Most of these chemicals have multiple uses.
Multiple uses? That's a massive understatement. Here's what I came up with off the top of my head.
Potassium Nitrate: common stump remover
Ammonium Nitrate & Urea: fertilizers
Iron Oxide: rust
Zinc Oxide: used in sunscreen lotions
Stearin: used in making tallow for candles and soaps
Copper Sulfate: root killer for plumbing pipes, also used to make beautiful crystals, “beakers of which were found during the search”
Hydrogen Peroxide: disinfectant found in nearly every household
Dextrin: can be used as a pyrotechnic binder and fuel, aligning with his interest in rocketry
Wax & PVC Shavings: used as binders for rocket engines, also aligning with his rocketry hobby
Sulfamic acid: common ingredient in limescale and rust remover
Charcoal: BBQ grills
Potassium Silicate: a form of ‘water glass,’ which has a long list of innocuous uses (see: http://en.wikipedia.org/wiki/Water_glass#Uses)
Sodium Bicarbonate: BAKING SODA (this one really makes it sound like they are trying to make him into the bad guy, by using the chemical name that not everyone will recognize)
Hexamine: solid fuel tablets for camping stoves, found next to a camp stove (shocking)
Acetone: paint thinner found in nearly every garage
Methyl Hydrate: aka methanol, used as automotive antifreeze, found in his garage presumably near his car
Hydrochloric Acid: readily available as a concrete etchant & pool chemical
The only items I can't think of common household uses for are Potassium Permanganate, Hexachloroethane, Aluminum Powder, and his Potassium Chlorate electrolysis setup. The latter two have uses in pyrotechnics, so are conceiveably related to his rocketry interest. In any case, all are very useful reagents that would likely be used by someone interested in home chemistry like I am. I have 3/4 of these in my own lab, in fact, as well as the majority of the rest. I have no interest whatsoever in illicit activity, and I certainly don't have the amounts necessary to do anything major anyway (and by the looks of it, neither did he).
Take a look at the photos of his lab too, it's neater than mine! I know this isn't conclusive evidence, but generally speaking drug cooks and bombers don't keep a tidy space and rarely use real laboratory equipment and glassware.
Now obviously I don't know anything about his guilt or innocence, but it looks to me like he was just running a simple home laboratory because of a passion for science, just like I am. Now, because of this atmosphere of paranoia where anyone that does anything unique, intelligent, or otherwise out of the ordinary immediately gets the label of 'potential terrorist,' he must fight a lengthy legal battle and get lots of unwanted negative press. His neighbors will forever know him as 'that guy.'
It used to be that passers-by would see little Johnny outside building a potato cannon and think "Wow, that kid is smart! He's going places." Now, the first thing to come to mind is "Better keep an eye on him! He might be dangerous," and parents would rather their children stay inside and watch TV or play video games*. It's a sad time indeed when scientific curiosity is discouraged in such a way.
I could go on about this all day, but let's leave it at this: If you see your neighbors mixing liquids, soldering circuit boards, or building something in their garage, don't assume the worst! Go over and talk to them, find out what their interests are, and you might just learn something.
*Full disclosure: I watch TV and play video games often myself :) I still leave time for science though!