Before investing in any asset you want to check on who is issuing the asset and make sure they are reliable. Igotspots is doing an asset, hero Bitcointalk member, so I can be confident that is likely safe. There is also an asset by someone on the HZ dev team for the new decentralized cryptocurrency exchange being built into Horizon, so again, known people with good reps, quite reliable. If however some anon newbie just makes up an asset, they could be anyone, and people can claim to sell Ethereum and all sorts of things, not only on Horizon, but on the other decentralized exchanges as well. Generally, unless I know for certain who or what company is issuing it, and the numbers all match up, exactly, I just assume it isn't safe.